tetrahydrofuran — label CAS 109-99-9

tetrahydrofuran

IARC Group 2B — Possibly carcinogenic to humans
CAS: 109-99-9 | IARC source

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REACH 2020/878
v2 · 15.07.2026
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3D model Tetrahydrofuran, CAS 109-99-9, molecular formula C4H8O, molar mass 72.11 g/mol
Chemical Overview: TetrahydrofuranMolGod_OVERVIEW_1
Molecular formulaC4H8O
Molecular weight72.11 g/mol
Melting point-108.4 °C
Boiling point65.95 °C
Density0.8833 g/cm³
LogP (lipophilicity)0.46
IUPAC nameoxolane
SMILESC1CCOC1
InChIKeyWYURNTSHIVDZCO-UHFFFAOYSA-N

Synonyms: TETRAHYDROFURAN · Oxolane · 109-99-9 · Furanidine · Furan, tetrahydro-

Data sources: PubChem (NLM/NIH), Reid, Prausnitz, Poling 4th ed. (1987)
Last updated: 2026-11-10

SCIENTIFIC RESEARCH

[1]EuropePMC2026
Toward Deep Dehydration of Tetrahydrofuran: Preparation and Application of a Microporous/Mesoporous Composite Adsorbent.
Yu, J; Qu, A; Ju, Z; Liu, N. 2026. "Toward Deep Dehydration of Tetrahydrofuran: Preparation and Application of a Microporous/Mesoporous Composite Adsorbent." Langmuir : the ACS journal of surfaces and
Go to full study ↗
[2]EuropePMC2026
Access to Regiodefined Tetrahydrofuran-3-one-Derived C-2 Silyl Enol Ethers from α-Triisopropylsilyl-α-diazoketones: The TIPS Trick.
Boullier, C; Gavelle, S; Lhoste, J; Henrion, S. 2026. "Access to Regiodefined Tetrahydrofuran-3-one-Derived C-2 Silyl Enol Ethers from α-Triisopropylsilyl-α-diazoketones: The TIPS Trick." Organic lett
Go to full study ↗
[3]EuropePMC2026
Skeletal editing of tetrahydrofurans to pyrrolidines through O-to-N single atom swap.
Geng, S; Wang, T; Kong, Q; Ouyang, D. 2026. "Skeletal editing of tetrahydrofurans to pyrrolidines through O-to-N single atom swap." Nature communications. https://doi.org/10.1038/s41467-026-71886-y.
Go to full study ↗
[4]EuropePMC2026
Redox Potentials for Hydrogen Species in Acetonitrile and Tetrahydrofuran.
Duda, DP; Sprouse, S; Hu, Y; Wiedner, ES. 2026. "Redox Potentials for Hydrogen Species in Acetonitrile and Tetrahydrofuran." The journal of physical chemistry. A. https://doi.org/10.1021/acs.jpca.6c00
Go to full study ↗
[5]EuropePMC2026
Liquid-Phase Synthesis of Lithium Argyrodite Sulfide Electrolytes Using Tetrahydrofuran and Water.
Hashii, T; Tanigaki, H; Furukawa, T; Kowada, H. 2026. "Liquid-Phase Synthesis of Lithium Argyrodite Sulfide Electrolytes Using Tetrahydrofuran and Water." Langmuir : the ACS journal of surfaces and co
Go to full study ↗
[6]EuropePMC2026
Effects of Pore Structure on Methane Adsorption and Diffusion Properties in Varying-Rank Coals Modified by Tetrahydrofuran.
Han, F; Zheng, C; Xue, S; Li, X. 2026. "Effects of Pore Structure on Methane Adsorption and Diffusion Properties in Varying-Rank Coals Modified by Tetrahydrofuran." Langmuir : the ACS journal of surfa
Go to full study ↗
[7]EuropePMC2026
Bisaspochalasin F: a tetrahydrofuran ring-fused cytochalasan homodimer from an endophytic <i>Aspergillus flavipes</i> as a Ca<sub>v</sub>3.2 inhibitor.
Wang, L; Liu, R; Yu, Z; Hou, CJ. 2026. "Bisaspochalasin F: a tetrahydrofuran ring-fused cytochalasan homodimer from an endophytic <i>Aspergillus flavipes</i> as a Ca<sub>v</sub&gt
Go to full study ↗
[8]EuropePMC2026
Effects of Isopropyl Alcohol, Tetrahydrofuran, Pyridine, and Acetonitrile on Surface Roughness, Surface Morphology, and Shear Bond Strength Between…
Thongsawas, N; Katheng, A; Kengtanyakich, S; Lekatana, H. 2026. "Effects of Isopropyl Alcohol, Tetrahydrofuran, Pyridine, and Acetonitrile on Surface Roughness, Surface Morphology, and Shear Bond Stre
Go to full study ↗
📚 Scientific references (Chicago Author-Date) 9 refs · 2 baz

MOLEKUŁA Per-CAS bibliography (live from 13+ databases)

Sources: db:europepmc (9)

  1. db:europepmc Wang, C; Rishi, K; Ku, BK; Kulkarni, P. 2026. "Compatibility of engineered stone materials with tetrahydrofuran processing for crystalline silica analysis by XRD." Annals of work exposures and health. https://doi.org/10.1093/annweh/wxaf052. →
  2. db:europepmc Yu, J; Qu, A; Ju, Z; Liu, N. 2026. "Toward Deep Dehydration of Tetrahydrofuran: Preparation and Application of a Microporous/Mesoporous Composite Adsorbent." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c01103. →
  3. db:europepmc Boullier, C; Gavelle, S; Lhoste, J; Henrion, S. 2026. "Access to Regiodefined Tetrahydrofuran-3-one-Derived C-2 Silyl Enol Ethers from α-Triisopropylsilyl-α-diazoketones: The TIPS Trick." Organic letters. https://doi.org/10.1021/acs.orglett.6c00147. →
  4. db:europepmc Geng, S; Wang, T; Kong, Q; Ouyang, D. 2026. "Skeletal editing of tetrahydrofurans to pyrrolidines through O-to-N single atom swap." Nature communications. https://doi.org/10.1038/s41467-026-71886-y. →
  5. db:europepmc Duda, DP; Sprouse, S; Hu, Y; Wiedner, ES. 2026. "Redox Potentials for Hydrogen Species in Acetonitrile and Tetrahydrofuran." The journal of physical chemistry. A. https://doi.org/10.1021/acs.jpca.6c00629. →
  6. db:europepmc Hashii, T; Tanigaki, H; Furukawa, T; Kowada, H. 2026. "Liquid-Phase Synthesis of Lithium Argyrodite Sulfide Electrolytes Using Tetrahydrofuran and Water." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.5c06765. →
  7. db:europepmc Han, F; Zheng, C; Xue, S; Li, X. 2026. "Effects of Pore Structure on Methane Adsorption and Diffusion Properties in Varying-Rank Coals Modified by Tetrahydrofuran." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c00630. →
  8. db:europepmc Wang, L; Liu, R; Yu, Z; Hou, CJ. 2026. "Bisaspochalasin F: a tetrahydrofuran ring-fused cytochalasan homodimer from an endophytic <i>Aspergillus flavipes</i> as a Ca<sub>v</sub>3.2 inhibitor." Organic & biomolecular chemistry. https://doi.org/10.1039/d6ob00028b. →
  9. db:europepmc Thongsawas, N; Katheng, A; Kengtanyakich, S; Lekatana, H. 2026. "Effects of Isopropyl Alcohol, Tetrahydrofuran, Pyridine, and Acetonitrile on Surface Roughness, Surface Morphology, and Shear Bond Strength Between Composite Resin and Different Provisional Restorative Materials." Dentistry journal. https://doi.org/10.3390/dj14050309. →
📊 Physicochemical properties

Quick Reference

Formula: C4H8O
MW: 72.11 g/mol
CAS: 109-99-9
Appearance: Colorless, mobile liquid
Odour: Ether-like odor
Odour: Ether-like odor

Detailed Properties

Property Value Unit Conditions Source
Density (ρ) 0.8833 g/cm³ 20 °C (68 °F) Reid, Prausnitz, Poling 4th ed. (1987)
Melting Point (mp) -108.40 °C (-163.1 °F) 1 atm Reid, Prausnitz, Poling 4th ed. (1987)
Boiling Point (bp) 65.95 °C (150.7 °F) 1 atm Reid, Prausnitz, Poling 4th ed. (1987)
Flash Point -14.00 °C (6.8 °F) closed cup Reid, Prausnitz, Poling 4th ed. (1987)
Vapor Pressure 162.000 mmHg 25 °C (77 °F) Reid, Prausnitz, Poling 4th ed. (1987)
Water Solubility miscible g/L 20 °C (68 °F) Reid, Prausnitz, Poling 4th ed. (1987)
Viscosity (η) 0.456 cP 25 °C (77 °F) Reid, Prausnitz, Poling 4th ed. (1987)
Refractive Index (nD) 1.4070 20 °C (68 °F), D-line Reid, Prausnitz, Poling 4th ed. (1987)
🔬 Advanced Properties
Surface Tension 26.400 mN/m 20°C
Dielectric Constant (ε) 7.520 25°C
Heat Capacity (Cp) 1.766 J/(g·K) 25°C

Chemical Identifiers

SMILES: C1CCOC1

Data sources: PubChem, NIST Chemistry WebBook, CRC Handbook of Chemistry and Physics (103rd ed.)

Last updated: 2026-06-09

Regulatory status of the substance
This substance is subject to regulatory requirements: hazardous waste management (BDO register); transport of dangerous goods (ADR/RID/IMDG). Details in the \"Regulatory Status (REACH/ECHA/CLP)\" section and on the SDS. Regulatory information — does not restrict purchase in this store.
🧮 Stoichiometry CalculatorMolGod_STOICH_1
🔍 External identifiersMolGod_EXTID_1
11 of 16 ID systems69%
DatabaseIdentifierActions
CAS Registry Number109-99-9Open →
PubChem CID8028Open →
InChIKeyWYURNTSHIVDZCO-UHFFFAOYSA-NOpen →
InChIInChI=1S/C4H8O/c1-2-4-5-3-1/h1-4H2
SMILESC1CCOC1
EC Number203-726-8Open →
HMDBHMDB0000246Open →
ChemSpider7737Open →
UNII (FDA)3N8FZZ6PY4Open →
NSC Number (NCI)57858Open →
WikiData QIDQ278332Open →

Sources: PubChem (NIH), Wikidata SPARQL, KEGG, ChEMBL (EBI), CompTox CTX (EPA).

📡 Spectroscopy — CAS 109-99-9MolGod_SPECHUB_MAIN
📊 Spectra (NMR, IR, MS, UV-Vis) (1)

Available spectrum types: IR

IR spectrum (KBr, 4000-400 cm⁻¹)

440 data points · Source: NIST WebBook · NIST ↗ · 📥 JCAMP-DX
📋 Peak assignment table
Type Position Intensity Assignment
IR 450 253 —
IR 452 76 —
IR 454 48 —
IR 456 76 —
IR 458 56 —
IR 490 89 —
IR 492 9 —
IR 494 33 —
IR 496 133 —
IR 498 55 —
IR 530 32 —
IR 532 111 —
IR 534 39 —
IR 536 93 —
IR 538 94 —
IR 570 44 —
IR 572 72 —
IR 574 64 —
IR 576 39 —
IR 578 62 —
🎓 Spectrum interpretation guide (for students)
How to read an IR spectrum
  • 3200-3600 cm⁻¹ — O-H stretch (broad peak = hydrogen bonding)
  • 2850-3000 cm⁻¹ — C-H stretch (sp³)
  • 1650-1750 cm⁻¹ — C=O stretch (ketones, aldehydes, esters)
  • 1400-1600 cm⁻¹ — aromatic ring vibrations
  • 1000-1300 cm⁻¹ — C-O stretch (ethers, alcohols)
  • No absorption = no functional group → compare with a reference

Sources: LibreTexts ↗, Silverstein (Spectrometric ID) ↗

📚 Scientific references (Chicago Author-Date) (9 sources)

📚 The book bibliography is awaiting generation. Curated general textbooks are available below; CAS-specific Google Books can be fetched from the admin panel.

  1. National Institute of Standards and Technology. 2024. "NIST Chemistry WebBook, SRD 69." Gaithersburg, MD: NIST. Accessed 2025-01-01. ↗
  2. Spectral Database for Organic Structure Determination (SDBS). 2024. National Institute of Advanced Industrial Science and Technology (AIST), Japan. Accessed 2025-01-01. ↗
  3. Ulrich, Eldon L., Hideo Akutsu, John F. Doreleijers, Yoko Harano, Yannis E. Ioannidis, Jundong Lin, Miron Livny, et al. 2008. "BioMagResBank." Nucleic Acids Research 36 (D1): D402–D408. [DOI ↗]
  4. Horai, Hisayuki, Masanori Arita, Shigehiko Kanaya, Yoshito Nihei, Tasuku Ikeda, Kazuhiro Suwa, Yuya Ojima, et al. 2010. "MassBank: A Public Repository for Sharing Mass Spectral Data for Life Sciences." Journal of Mass Spectrometry 45 (7): 703–714. [DOI ↗]
  5. Linstrom, P.J., and W.G. Mallard, eds. 2024. NIST Chemistry WebBook, NIST Standard Reference Database Number 69. Gaithersburg, MD: National Institute of Standards and Technology. ↗
  6. McDonald, M. Shane, Mike McAvoy, and Ajit Bhalerao. 1988. "JCAMP-DX: A Standard Form for Exchange of Infrared Spectra in Computer Readable Form." Applied Spectroscopy 42 (1): 151–162. [DOI ↗]
  7. PubChem. 2024. "PubChem Compound Database." National Library of Medicine, National Institutes of Health. Accessed 2025-01-01. ↗
📐 Physical & Chemical Properties (DB) 22 fields MolGod Score: Primary
Property Value Unit Conditions Source
Melting point -108.40 [4][6][11] °C 1 atm Reid, Prausnitz, Poling 4th ed. (1987)
Boiling point 65.95 [4][6][11] °C 760 mmHg Reid, Prausnitz, Poling 4th ed. (1987)
Water solubility miscible [4] g/L 20°C Reid, Prausnitz, Poling 4th ed. (1987)
Density (ρ) 0.8833 [4] g/cm³ 20°C Reid, Prausnitz, Poling 4th ed. (1987)
Refractive index (n_D) 1.4070 [4] — 20°C, sodium D Reid, Prausnitz, Poling 4th ed. (1987)
Viscosity (η) 0.456 [4] cP 25°C Reid, Prausnitz, Poling 4th ed. (1987)
Vapor pressure 162.000 [4] mmHg 25°C Reid, Prausnitz, Poling 4th ed. (1987)
Flash point -14.00 [4] °C closed cup Reid, Prausnitz, Poling 4th ed. (1987)
Autoignition temperature 321.00 [4] °C in air Reid, Prausnitz, Poling 4th ed. (1987)
logP (octanol/water) 0.460 [4][8][9] — 25°C Reid, Prausnitz, Poling 4th ed. (1987)
logD (pH 7) 0.460 [4][8][9] — pH 7.4 Reid, Prausnitz, Poling 4th ed. (1987)
Dielectric constant (ε) 7.520 [4] — 25°C Reid, Prausnitz, Poling 4th ed. (1987)
Surface tension 26.400 [4] mN/m 20°C Reid, Prausnitz, Poling 4th ed. (1987)
Specific heat (cp) 1.766 [4] J/(g·K) 25°C Reid, Prausnitz, Poling 4th ed. (1987)
Thermal conductivity (k) 0.1200 [4] W/(m·K) 25°C Reid, Prausnitz, Poling 4th ed. (1987)
Dipole moment (μ) 1.630 [4] D gas phase Reid, Prausnitz, Poling 4th ed. (1987)
ΔH vaporization 31.990 [4] kJ/mol NBP Reid, Prausnitz, Poling 4th ed. (1987)
ΔH fusion 8.540 [4] kJ/mol at mp Reid, Prausnitz, Poling 4th ed. (1987)
Critical temperature (Tc) 267.00 [4] °C critical point Reid, Prausnitz, Poling 4th ed. (1987)
Critical pressure (Pc) 51.900 [4] bar critical point Reid, Prausnitz, Poling 4th ed. (1987)
Acentric factor (ω) 0.2250 [4] — Pitzer Reid, Prausnitz, Poling 4th ed. (1987)
Ethanol solubility miscible [4] g/L 25°C Reid, Prausnitz, Poling 4th ed. (1987)
📚 Scientific references (Chicago Author-Date) (12 sources)
  1. Haynes, William M., ed. 2024. CRC Handbook of Chemistry and Physics. 105th ed. Boca Raton: CRC Press/Taylor & Francis. ISBN 978-1-032-55554-4. ↗
  2. National Institute of Standards and Technology. 2024. "NIST Chemistry WebBook, SRD 69." Gaithersburg, MD: NIST. Accessed 2025-01-01. ↗
  3. Yaws, Carl L. 2014. The Yaws Handbook of Physical Properties for Hydrocarbons and Chemicals. 2nd ed. Oxford: Gulf Professional Publishing.
  4. PubChem. 2024. "PubChem Compound Database." National Library of Medicine, National Institutes of Health. Accessed 2025-01-01. ↗
  5. Marrero, J., and R. Gani. 2001. "Group-Contribution Based Estimation of Pure Component Properties." Fluid Phase Equilibria 183–184: 183–208. ↗
  6. Joback, K. G., and R. C. Reid. 1987. "Estimation of Pure-Component Properties from Group-Contributions." Chemical Engineering Communications 57 (1–6): 233–243. ↗
  7. Sangster, J. 1997. Octanol-Water Partition Coefficients: Fundamentals and Physical Chemistry. Chichester: Wiley. ISBN 978-0-471-97397-3.
  8. Mannhold, Raimund, and Han van de Waterbeemd. 2001. "Substructure and Whole Molecule Approaches for Calculating Log P." Journal of Computer-Aided Molecular Design 15 (4): 337–354. ↗
  9. Perrin, Ditlev D., Boyd Dempsey, and E. P. Serjeant. 1981. pKa Prediction for Organic Acids and Bases. London: Chapman and Hall. ISBN 0-412-21090-5.
  10. Constantinou, Leonidas, and Rafiqul Gani. 1994. "New Group Contribution Method for Estimating Properties of Pure Compounds." AIChE Journal 40 (10): 1697–1710. ↗
  11. Ertl, Peter, Bernhard Rohde, and Paul Selzer. 2000. "Fast Calculation of Molecular Polar Surface Area as a Sum of Fragment-Based Contributions and Its Application to the Prediction of Drug Transport Properties." Journal of Medicinal Chemistry 43 (20): 3714–3717. ↗
🔄 Concentration unit converter LIVE MolGod_UNITCONV_1

Enter the Tetrahydrofuran concentration in any unit — the rest will be calculated automatically.

MW: 72.11 g/mol · IUPAC Gold Book ↗

⚗️ Conversion formulas + citations (per formula)
ConversionFormulaAccuracySource
% (w/v) ↔ molarityc (mol/L) = (% × 10) / MW±0.5% rel. when density ≈ 1.0 g/mLIUPAC (2019)
millimolar ↔ molarc (mol/L) = mM × 10⁻³ExactCohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007)
molarity (mol/L)c = n/V = (m/MW)/V±0.1% (depends on MW precision)IUPAC (2019)
parts per million (mg/L) ↔ molarityc (mol/L) = ppm / (1000 × MW); equivalently ppm = mg/L for dilute aqueous±1% (density-independent for dilute solutions)IUPAC (2019)
mg/mL ↔ molarityc (mol/L) = (mg/mL × 1000) / MW / 1000 = mg/mL / MW × 1±0.2%Cohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007)
g/L ↔ molarityc (mol/L) = (g/L) / MW±0.1% (depends on MW precision)Cohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007)
mmol/L ↔ molarityc (mol/L) = mmol/L × 10⁻³ExactCohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007)
Celsius ↔ KelvinT(K) = t(°C) + 273.15±0.01 K (ITS-90 scale)BIPM (Bureau International des Poids et Mesures) (2019)
Celsius ↔ FahrenheitT(°F) = T(°C) × 9/5 + 32±0.1 °FThompson A, Taylor BN (2008)
density-corrected % ↔ molarityc (mol/L) = (%w/w × ρ × 10) / MW, ρ in g/mL±0.1% when ρ known to 3 decimalsCohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007)
📚 Bibliography (8 authoritative sources)
  1. Thompson A, Taylor BN (2008). Guide for the Use of the International System of Units (SI). NIST Special Publication 811 · DOI: 10.6028/NIST.SP.811-2008
    → Primary SI standard for US scientific usage
  2. Cohen ER, Cvitaš T, Frey JG, Holmström B, Kuchitsu K, Marquardt R, Mills I, Pavese F, Quack M, Stohner J, Strauss HL, Takami M, Thor AJ (2007). Quantities, Units and Symbols in Physical Chemistry — The IUPAC Green Book. RSC Publishing, 3rd ed. · DOI: 10.1039/9781847557889 · ISBN: 978-0-85404-433-7
    → Canonical IUPAC guide for chemistry quantities/units
  3. BIPM (Bureau International des Poids et Mesures) (2019). The International System of Units (SI), 9th edition. BIPM · ↗
    → International SI definitions (incl. redefined kilogram 2019)
  4. ISO/IEC (2022). Quantities and units — Part 1: General. International Organization for Standardization — ISO 80000-1:2022 · ↗
    → General rules for physical quantities and units
  5. ISO/IEC (2019). Quantities and units — Part 9: Physical chemistry and molecular physics. International Organization for Standardization — ISO 80000-9:2019 · ↗
    → Concentration / molality / amount-of-substance conventions
  6. Tiesinga E, Mohr PJ, Newell DB, Taylor BN (2021). CODATA recommended values of the fundamental physical constants: 2018. Rev. Mod. Phys. 93(2):025010 · DOI: 10.1103/RevModPhys.93.025010
    → Avogadro, gas constant, molar volume (2019 SI revision)
  7. IUPAC (2019). Compendium of Chemical Terminology — the IUPAC Gold Book (online). IUPAC · DOI: 10.1351/goldbook
    → Definitions of mass fraction, molality, normality, ppm, activity
  8. Mills IM, Cvitaš T, Homann K, Kallay N, Kuchitsu K (1988). Quantities, Units and Symbols in Physical Chemistry. Blackwell Scientific Publications, 1st ed. · ISBN: 0-632-01773-5
    → Historical predecessor of IUPAC Green Book
🧪 Solution Preparation Wizard WIZARD MolGod_PREP_1
① Select concentration
② Target volume
③ Solvent

Calculations per: IUPAC Gold Book ↗, Merck ↗

Solvent compatibilityMolGod_SOLV_1

Estimate based on water solubility and logP. Indicative data — does not replace experimental studies.

SolventCompatibilityNotesReferences
Water~ ModerateModerate logP
EtOH+ GoodEtOH — universal polar solvent
Acetone+ GoodAcetone — good for moderately polar compounds
DCM+ GoodDCM — good for nonpolar compounds
DMSO+ GoodDMSO — strong aprotic solvent
THF+ GoodTHF — broad solubility range
Hexane- PoorPoor solubility in hexane
CHCl3+ GoodCHCl3 — good for moderately polar and nonpolar compounds

Data sources for logP/solubility: logP: 0.50

📚 Scientific references for solvents (Chicago Author-Date) — click to expand

Each solvent is supported by 5 independent scientific sources (NIST/CRC/IARC/Hansen/Reichardt/Smallwood/GESTIS). Full citations below.

Water · NIST CAS lookup ↗
  1. Rumble, John R., ed. 2023. CRC Handbook of Chemistry and Physics. 104th ed. Boca Raton, FL: CRC Press. [link ↗]
  2. International Association for the Properties of Water and Steam (IAPWS). 1997. "Release on the Static Dielectric Constant of Ordinary Water Substance." IAPWS R8-97. [link ↗]
  3. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. https://doi.org/10.1002/9783527632220. [link ↗]
  4. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. https://doi.org/10.1201/9781420006834. [link ↗]
  5. IFA. n.d. "Water." GESTIS Substance Database. Institut für Arbeitsschutz der Deutschen Gesetzlichen Unfallversicherung. Accessed April 25, 2026. [link ↗]
EtOH · NIST CAS lookup ↗
  1. Rumble, John R., ed. 2023. CRC Handbook of Chemistry and Physics. 104th ed. Boca Raton, FL: CRC Press. [link ↗]
  2. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. https://doi.org/10.1002/9783527632220. [link ↗]
  3. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. Hoboken, NJ: Wiley. https://doi.org/10.1002/9780470508183. [link ↗]
  4. Smallwood, Ian M. 1996. Handbook of Organic Solvent Properties. London: Arnold. https://doi.org/10.1016/B978-0-340-64578-9.X5000-9. [link ↗]
  5. IFA. n.d. "Ethanol." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
Acetone · NIST CAS lookup ↗
  1. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. https://doi.org/10.1002/9783527632220. [link ↗]
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  3. Rumble, John R., ed. 2023. CRC Handbook of Chemistry and Physics. 104th ed. Boca Raton, FL: CRC Press. [link ↗]
  4. Smallwood, Ian M. 1996. Handbook of Organic Solvent Properties. London: Arnold. [link ↗]
  5. IFA. n.d. "Acetone." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
DCM · NIST CAS lookup ↗
  1. National Institute of Standards and Technology. n.d. "Methane, dichloro- (CAS 75-09-2)." NIST Chemistry WebBook, SRD 69. Accessed April 25, 2026. [link ↗]
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  3. International Agency for Research on Cancer. 1999. "Dichloromethane." IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 71: 251–315. [link ↗]
  4. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. [link ↗]
  5. IFA. n.d. "Dichloromethane." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
DMSO · NIST CAS lookup ↗
  1. Wypych, George. 2019. Handbook of Solvents. Volume 1: Properties. 3rd ed. Toronto: ChemTec Publishing. https://doi.org/10.1016/C2018-0-02235-3. [link ↗]
  2. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. [link ↗]
  3. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  4. National Institute of Standards and Technology. n.d. "Methane, sulfinylbis- (CAS 67-68-5)." NIST Chemistry WebBook. Accessed April 25, 2026. [link ↗]
  5. IFA. n.d. "Dimethyl sulfoxide." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
THF · NIST CAS lookup ↗
  1. Armarego, Wilfred L. F., and Christina Li Lin Chai. 2009. Purification of Laboratory Chemicals. 6th ed. Oxford: Butterworth-Heinemann. https://doi.org/10.1016/B978-1-85617-567-8.50003-3. [link ↗]
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  3. National Institute of Standards and Technology. n.d. "Furan, tetrahydro- (CAS 109-99-9)." NIST Chemistry WebBook. Accessed April 25, 2026. [link ↗]
  4. Smallwood, Ian M. 1996. Handbook of Organic Solvent Properties. London: Arnold. [link ↗]
  5. IFA. n.d. "Tetrahydrofuran." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
Hexane · NIST CAS lookup ↗
  1. National Institute of Standards and Technology. n.d. "Hexane (CAS 110-54-3)." NIST Chemistry WebBook. Accessed April 25, 2026. [link ↗]
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  3. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. Hoboken, NJ: Wiley. [link ↗]
  4. Agency for Toxic Substances and Disease Registry. 1999. Toxicological Profile for n-Hexane. Atlanta, GA: U.S. Department of Health and Human Services. [link ↗]
  5. IFA. n.d. "n-Hexane." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
CHCl3 · NIST CAS lookup ↗
  1. International Agency for Research on Cancer. 1999. "Chloroform." IARC Monographs on the Evaluation of Carcinogenic Risks to Humans 73: 131–182. [link ↗]
  2. National Institute of Standards and Technology. n.d. "Methane, trichloro- (CAS 67-66-3)." NIST Chemistry WebBook. Accessed April 25, 2026. [link ↗]
  3. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. [link ↗]
  4. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. [link ↗]
  5. IFA. n.d. "Chloroform." GESTIS Substance Database. Accessed April 25, 2026. [link ↗]
Solubility theory (applied in compatibility prediction):
  1. Yalkowsky, Samuel H., and Shri C. Valvani. 1980. "Solubility and Partitioning I: Solubility of Nonelectrolytes in Water." Journal of Pharmaceutical Sciences 69 (8): 912–922. https://doi.org/10.1002/jps.2600690814 — General Solubility Equation (GSE): logS = 0.5 − logP − 0.01(MP−25).
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. Boca Raton, FL: CRC Press. https://doi.org/10.1201/9781420006834 — HSP triplet (dD, dP, dH) + Ra formula.
  3. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Weinheim: Wiley-VCH. https://doi.org/10.1002/9783527632220 — E_T(30) polarity scale, solwatochromia.
  4. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. Hoboken, NJ: Wiley. https://doi.org/10.1002/9780470508183 — Eluotropic series, polarity index.
  5. PubChem Compound Database — CAS 109-99-9 lookup ↗ — logP (XLogP3), water solubility experimental + predicted.

Full bibliography in the REFERENCES accordion (at the bottom of the page) — Chicago Manual of Style 17th ed., Author-Date.

🛡️ Safety — CAS 109-99-9MolGod_SAFEHUB_MAIN
Data limitations notice. The safety information on this page is for reference only and does not replace a full safety data sheet (SDS). Before using the product, consult the manufacturer's current safety data sheet and the GHS/CLP guidance. The CLP classification applies to the pure bulk substance, not to commercial formulations.

GHS/CLP classification — Regulation (EC) No 1272/2008 + UN GHS Rev. 9 (2021).

⚠️ Danger
GHS02 — Flammable
GHS02 Flammable
GHS07 — Irritant / harmful
GHS07 Irritant / harmful
GHS08 — Health hazard
GHS08 Health hazard

🚨 Hazard statements (H)

  • H225 — Highly flammable liquid and vapour
  • H351 — Suspected of causing cancer
  • H335 — May cause respiratory irritation
  • H319 — Causes serious eye irritation
  • EUH019

🛡 Precautionary statements (P)

  • P203 — Obtain, read and follow all safety instructions before use
  • P264 — Wash thoroughly after handling
  • P210 — Keep away from heat, hot surfaces, sparks, open flames and other ignition sources. No smoking

✓ Harmonised classification pursuant to Annex VI of the CLP Regulation (EC) 1272/2008 (official, binding classification). Index number: 603-025-00-0.

Reference (Chicago): European Chemicals Agency. "tetrahydrofuran, Index No. 603-025-00-0." In Table 3 of Annex VI to Regulation (EC) No 1272/2008 (CLP Regulation), 23rd Adaptation to Technical Progress. Helsinki: European Chemicals Agency, 2026. https://echa.europa.eu/information-on-chemicals/annex-vi-to-clp.

⚠ IARC — Group 2B: possibly carcinogenic to humans. (Independent assessment of carcinogenicity evidence by IARC/WHO — supplements the CLP classification above.)
Reference (Chicago): IARC. 2026. IARC Monographs on the Identification of Carcinogenic Hazards to Humans: CAS 109-99-9. Lyon, France: International Agency for Research on Cancer, World Health Organization. https://monographs.iarc.who.int/list-of-classifications/. (Accessed 2026-11-12.)
Classification from the local MOL-GOD list (snapshot) — unverified against the current IARC list. Verify

Translations: CLP Regulation (EC) 1272/2008, Annexes III and IV. Data: PubChem/NLM.

📚 Consolidated scientific references — Chicago Author-Date 10 sources

References collected from all Safety Hub tabs. CAS: 109-99-9 · PubChem ↗

  1. Parlament Europejski i Rada UE. 2008. "Rozporządzenie (WE) nr 1272/2008 w sprawie klasyfikacji, oznakowania i pakowania substancji (CLP)." Dz.Urz. UE L 353. [↗] GHS, Regulations
  2. United Nations Economic Commission for Europe (UNECE). 2021. "Globally Harmonized System of Classification and Labelling of Chemicals (GHS), Ninth Revised Edition." United Nations, Geneva. [↗] GHS
  3. Goldfrank, Lewis R., Robert S. Hoffman, Mary Ann Howland, et al.. 2019. "Goldfrank's Toxicologic Emergencies, 11th ed.." McGraw-Hill Education, New York. ISBN 978-1-25-985961-8. Pierwsza pomoc, Toksykologia
  4. National Institute for Occupational Safety and Health (NIOSH). 2023. "NIOSH Pocket Guide to Chemical Hazards (DHHS Publ. 2005-149)." U.S. Department of Health and Human Services / CDC, Cincinnati, OH. [↗] Pierwsza pomoc, PPE, Toksykologia
  5. European Committee for Standardization (CEN). 2016. "EN 374-1:2016 — Protective gloves against dangerous chemicals and micro-organisms." CEN, Brussels. [↗] PPE
  6. UNECE. 2023. "European Agreement Concerning the International Carriage of Dangerous Goods by Road (ADR 2025)." United Nations, Geneva. [↗] Utylizacja, Regulacje
  7. National Fire Protection Association (NFPA). 2022. "NFPA 400 — Hazardous Materials Code." NFPA, Quincy, MA. [↗] Magazynowanie
  8. Urben, P.G. (ed.). 2017. "Bretherick's Handbook of Reactive Chemical Hazards, 8th ed.." Butterworth-Heinemann / Elsevier, Oxford. [↗] Magazynowanie
  9. Ministerstwo Klimatu i Środowiska RP. 2023. "Baza danych o produktach i opakowaniach oraz o gospodarce odpadami (BDO)." Ministerstwo Klimatu i Środowiska, Warszawa. [↗] Utylizacja
  10. International Agency for Research on Cancer (IARC / WHO). 2024. "IARC Monographs on the Identification of Carcinogenic Hazards to Humans — List of Classifications." WHO, Lyon. [↗] Toksykologia

Tabs with their own references (Emergency, PPE, Storage, Waste) contain additional bibliographic entries within their respective sections.

📈 Analytical statistics (t-test · RSD · Grubbs · Q-Dixon) ICH Q2

Paste a series of replicate measurements (CSV, or one number per line). The calculator computes the mean, standard deviation and 95% CI, and detects outliers (Grubbs + Dixon Q).

Separator: comma, space, tab, new line. Minimum 3 measurements.
📐 Statistical formulas
  • x̄ = Σxᵢ / n — arithmetic mean
  • s² = Σ(xᵢ - x̄)² / (n-1) — sample variance
  • s = √s² — standard deviation
  • RSD% = (s / x̄) × 100% — relative standard deviation
  • CI₉₅ = x̄ ± t(0.05, n-1) × s / √n — Student's t
  • G = |xᵢ - x̄| / s — Grubbs' test
  • Q = |xsuspect - xnearest| / |xmax - xmin| — Dixon Q-test

Source: ICH Q2(R2) Validation of Analytical Procedures · ICH PDF ↗

🧪 Buffer Recipe Calculator UNIQUE
References: pKa values from Goldberg NIST 81 · CRC Handbook 100th ed. · Stoll & Blanchard 1990 (DOI)

Choose a buffer from the list of 20 popular systems → enter the target pH → get an exact recipe with the masses to weigh out.

Step 1: Choose a buffer system

📜 Recipe history (last 10)
🚚 Transport classification (ADR / IATA / IMDG) UN2056
UN Number
UN2056
TETRAHYDROFURAN
Flammable Peroxide former

🛣️ ADR Road Transport

Class:
3
Packing Group:
II
Shipping name:
TETRAHYDROFURAN
Tunnel Code:
(D/E)
Limited Quantity (L):
1

✈️ IATA Air Transport

Class:
3
Packing instructions:
353 / 364
Max quantity (PAX):
5 L
Max quantity (CAO):
60 L

🚢 IMDG Sea Transport

Class:
3
EmS Code:
F-E, S-D

Sources: ADR 2025 ↗ · IATA DGR ↗ · IMDG Code ↗

🔬 HPLC/GC methods (1 method)
📄
Comprehensive SPME-GC-MS Analysis of VOC Profiles Obtained Following High-Temperature Heating of Pork Back Fat with Varying Boar Taint Intensities
GC-MSFoods202193% ✓CC-BYResearch method (specificity, robustness)
Column: C18, 150 x 3.0 mm, 0.45 μm
Phase: mobile phase are prepared as follows: (A) H3PO4/deionized water (1:1000 v/v)
Detection: UV 285 nm
Flow: 0.50 mL/min
Temp.: 20.0 °C
Inj.: 500 μL
Gradient: profile runs as presented in Table 1
Burgeon C, Markey A, Debliquy M, Lahem D, Rodriguez J, Ly A, et al. Comprehensive SPME-GC-MS Analysis of VOC Profiles Obtained Following High-Temperature Heating of Pork Back Fat with Varying Boar Taint Intensities. Foods. 2021;10:1311. doi:10.3390/foods10061311
🔗 DOI🏠 PMC📚 PubMed📄 PDF
Boar taint detection is a major concern for the pork industry. Currently, this taint is mainly detected through a sensory evaluation. However, little is known about the entire volatile organic compounds (VOCs) profile perceived by the assessor. Additionally, many research groups are working on the development of new rapid and reliable detection methods, which include the VOCs sensor-based methods. The latter are susceptible to sensor poisoning by interfering molecules produced during high-temperature heating of fat. Analyzing the VOC profiles obtained by solid phase microextraction gas chromatography–mass spectrometry (SPME-GC-MS) after incubation at 150 and 180 °C helps in the comprehension of the environment in which boar taint is perceived. Many similarities were observed between these temperatures; both profiles were rich in carboxylic acids and aldehydes. Through a principal component analysis (PCA) and analyses of variance (ANOVAs), differences were highlighted. Aldehydes such as (E,E)-nona-2,4-dienal exhibited higher concentrations at 150 °C, while heating at 180 °C resulted in significantly higher concentrations in fatty acids, several amide derivatives, and squalene. These differences stress the need for standardized parameters for sensory evaluation. Lastly, skatole and androstenone, the main compounds involved in boar taint, were perceived in the headspace at these temperatures but remained low (below 1 ppm). Higher temperature should be investigated to increase headspace concentrations provided that rigorous analyses of total VOC profiles are performed.
back fatboar taintentire male pigGC-MSlipid oxidationmeat qualitypork meatSPME
📈 Method Validation (ICH Q2)

No validation data. Contact the method author.

Parameters per: ICH Q2(R2) ↗

🔧 Troubleshooting HPLC/GC
Broad peaks / tailing
Causes: Worn column, wrong mobile-phase pH, column overload, dead volume
Solution: Replace the column, check buffer pH (±0.2), reduce injection volume, check fittings
Baseline drift
Causes: Contaminated mobile phase, gradient issues, unstable temperature
Solution: Degas the phase, filter 0.22 µm, stabilise column temperature, flush the system
No peak
Causes: Wrong wavelength, analyte does not elute, thermal decomposition, wrong phase
Solution: Check λmax, extend the gradient, lower the temperature, change the mobile phase
Ghost peaks
Causes: System contamination, carry-over, contaminated vials
Solution: Clean the system (MeOH/H₂O), use new vials, inject a blank
Low recovery
Causes: Adsorption to walls, insufficient extraction, decomposition
Solution: Add IS, silanise glassware, optimise extraction, check stability

Sources: Snyder, Kirkland & Dolan ↗, Waters ↗

📊 HPLC method validation (ICH Q2(R1)) PARTIAL

3 metrics need experimental data

Parameter Value Unit ICH Q2 criterion Status
Linearity (R²) no data unitless R² ≥ 0.999 (≥0.99 for bioanalytical) —
LOD (S/N = 3:1) no data ng/mL S/N ≥ 3:1 (lowest detectable concentration) —
LOQ (S/N = 10:1) no data ng/mL S/N ≥ 10:1 (LOQ ≥ 3×LOD typically) —
Precision (RSD intraday, n=6) no data % RSD RSD ≤ 2% (intraday) / ≤ 3% (interday) for the API —
Accuracy (recovery, 3 levels) no data % (target 100±2%) Recovery 98-102% (target 100%) —
Linearity range no data e.g. 0.1-100 ng/mL Min. 80-120% of the nominal concentration —
Selectivity/Specificity no data qualitative No interference — analyte peak fully resolved (Rs ≥ 2.0) —
Robustness no data RSD < 2% at ±5% variation RSD < 2% under small parameter variations —
Legend: ✓ PASS ⚠ CAUTION ✗ FAIL — NO_DATA
📚 Scientific references (Chicago Author-Date) — click to expand

Analytical method validation standards — 4 independent sources (ICH + USP + AOAC + Snyder).

  1. International Conference on Harmonisation (ICH). 2005. Validation of Analytical Procedures: Text and Methodology Q2(R1). ICH Expert Working Group. [link ↗] — Gold-standard ICH guideline — accepted by EMA, FDA, MHLW, NMPA
  2. United States Pharmacopeia (USP) Convention. 2024. USP General Chapter <621> Chromatography. USP-NF 2024 ed. USP. [link ↗]
  3. AOAC International. 2016. Appendix F: Guidelines for Standard Method Performance Requirements. AOAC INTERNATIONAL. [link ↗] — AOAC SMPR — alternative to ICH Q2 for food/dietary supplements
  4. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. John Wiley & Sons. ISBN 978-0-470-16754-0. https://doi.org/10.1002/9780470508183 [link ↗] — Industry standard textbook — Chapter 11 covers method validation
  5. Snyder, L. R., J. J. Kirkland, and J. L. Glajch. 1997. Practical HPLC Method Development. 2nd ed. Wiley. ISBN 978-0-471-00703-6. — Classic method-development reference (DryLab heritage).
  6. Rozet, Eric, et al.. 2013. Analysis of recent pharmaceutical regulatory documents on analytical method validation. https://doi.org/10.1016/j.chroma.2007.03.111 [link ↗] — Comparison of FDA / EMA / ICH validation expectations — used for ICH Q2(R1) interpretation.
  7. Heyden, Yvan Vander, et al.. 2009. Robustness of pharmaceutical liquid chromatographic methods. https://doi.org/10.1016/j.jchromb.2008.10.052 [link ↗] — Plackett-Burman design for robustness — basis of ICH Q2 §3.7.
  8. Dong, Michael W.. 2019. HPLC and UHPLC for Practicing Scientists. 2nd ed. Wiley. ISBN 978-1-119-31378-3. https://doi.org/10.1002/9781119313793 [link ↗] — Modern (UHPLC) update of validation chapter — practical RSD/LOD examples.
  9. Meyer, Veronika R.. 2010. Practical High-Performance Liquid Chromatography. 5th ed. Wiley. ISBN 978-0-470-68218-0. — European pharmacopeial perspective — complements USP/AOAC.
  10. Kazakevich, Yuri V., and Rosario LoBrutto, eds.. 2007. HPLC for Pharmaceutical Scientists. Wiley-Interscience. ISBN 978-0-471-68162-4. https://doi.org/10.1002/9780470087954 [link ↗] — Pharma-focused validation case studies (specificity, robustness).
  11. European Medicines Agency (EMA). 2011. Guideline on bioanalytical method validation EMEA/CHMP/EWP/192217/2009. EMA Committee for Medicinal Products for Human Use. [link ↗] — EMA bioanalytical companion to ICH Q2(R1) for clinical samples.

· ⚠ SVHC/REACH regulatory warnings ↑

🔧 HPLC troubleshooting — decision tree 6 common problems

Diagnostics for the 12 most common HPLC problems with a decision tree (5 steps per problem). Source: Snyder/Kirkland/Dolan 3rd ed. Chapter 17 + LCGC LC Troubleshooting columns 1989-2024.

Broad peaks medium

Symptom: All peaks on the chromatogram are wider than expected (FWHM > 2× normal)

🔍 Diagnostic tree:
  1. 1. Check whether all peaks are broadened or only some
    → YES: All → instrumental problem (column or system)
    → NO: Only some → chemistry problem (interaction with the column for specific analytes)
  2. 2. Swap in a test column — does the problem disappear?
    → YES: COLUMN worn out — packing damaged, void in the first few mm. Replace it.
    → NO: Problem in the LC system
  3. 3. Check the dead volume — injection loop, connections, detector
    → YES: Loop > 100 µL for a 4.6 mm column or loose connections → replace ferrules, shorten tubing
    → NO: Continue diagnostics
  4. 4. Temperature test: raise the column from 25°C to 40°C
    → YES: Narrower peaks → mass-transfer kinetics too slow (increase T)
    → NO: Continue
  5. 5. Check flow rate vs the optimal van Deemter value for this column
    → YES: Optimum for 4.6mm/5µm = 1.0 mL/min, for 2.1mm/3µm = 0.4 mL/min
    → NO: Continue
⚠️ Common causes:
  • Column worn out (>2000 injections without a guard)
  • System dead volume > 100 µL (wrong loop, long tubing, loose ferrules)
  • Temperature too low (mass-transfer kinetics)
  • Flow rate outside the van Deemter optimum
  • Sample solvent stronger than mobile phase A
✓ Fixes:
  • ✓ Replace the column (when >2000 injections)
  • ✓ Check all connections — keep tubing as short as possible
  • ✓ Increase column T to 40°C (if the substance is stable)
  • ✓ Reduce flow to the van Deemter optimum
  • ✓ Dissolve the sample in mobile phase A (not in pure organic)
Peak tailing (T > 1.5) high

Symptom: Peaks have an extended "tail" on the late-elution side (asymmetry T = b/a > 1.5 per USP)

🔍 Diagnostic tree:
  1. 1. Does the substance contain basic groups (amino, pyridine)?
    → YES: Yes → silanol interactions! Add 0.1% TFA or 5-10 mM TEA to mobile phase A.
    → NO: Continue
  2. 2. Check the mobile-phase pH vs the substance pKa
    → YES: pH = pKa ± 1 → partial ionization, peak split. Move pH ≥ 2 units away from pKa.
    → NO: Continue
  3. 3. Check the column age (>1500 injections?)
    → YES: Yes → exposed silanols (column bleed). Replace with a column with higher endcapping (XTerra, Symmetry).
    → NO: Continue
  4. 4. Does the sample contain metals (Fe, Cu from glass vials)?
    → YES: Yes → use type II clear vials or PFA. Add 0.1mM EDTA to the sample.
    → NO: Continue
⚠️ Common causes:
  • Silanol interactions (basic analyte + silica gel free silanols)
  • pH at the boundary of the analyte pKa (peak split)
  • Old column (column bleed, high silanol activity)
  • Metals in the sample (chelation → tailing)
  • Column overload (>50 µg on a 4.6mm column)
✓ Fixes:
  • ✓ Add 0.1% TFA (UV) or 0.1% formic acid (LC-MS) to mobile phase A
  • ✓ Choose a column with high-purity endcapping: Waters XBridge BEH, Phenomenex Kinetex
  • ✓ Work at pH ≥ 2 units away from pKa
  • ✓ Add 0.1mM EDTA to the sample (Fe/Cu chelation)
  • ✓ Reduce the injection volume to ≤ 20 µL for a 4.6mm column
Baseline drift medium

Symptom: The baseline rises or falls systematically for >5 minutes

🔍 Diagnostic tree:
  1. 1. Are you running a gradient (B% increasing)?
    → YES: Yes → different absorption of phases A vs B at dλ. Solvent change in UV cutoff. Check the % organic UV absorbance.
    → NO: Continue (isocratic)
  2. 2. Check the column temperature — is it stable to ±0.5°C?
    → YES: Yes (stable) → continue
    → NO: Unstable → turn on the column thermostat (>25°C controlled)
  3. 3. Test: turn off the autosampler, run pump+column+detector alone
    → YES: Drift disappears → autosampler contamination (clean the needle, septum)
    → NO: Continue
  4. 4. Check the lamp age (D2 for UV)
    → YES: Yes (>1500 hours) → replace the lamp
    → NO: Continue
⚠️ Common causes:
  • Gradient elution with different UV cutoff of the phases
  • Unstable column T
  • Autosampler contamination of the needle/septum
  • Old UV lamp (>1500h)
  • Detector flow cell fouled
  • Column not equilibrated (<10 column volumes)
✓ Fixes:
  • ✓ Pre-equilibrate the column for 10-15 column volumes at 100% A
  • ✓ Column thermostat on, T 30-40°C stable
  • ✓ Clean the detector flow cell with 50:50 ACN:H2O
  • ✓ Replace the D2 lamp if >1500h
  • ✓ Use baseline subtraction (Chromeleon, Empower native function)
No peak / lost peak critical

Symptom: The expected analyte peak does not appear on the chromatogram

🔍 Diagnostic tree:
  1. 1. Did the injection actually take place?
    → YES: Check the autosampler log, pump pressure (should drop during injection)
    → NO: Autosampler problem → check the loop, needle, sample in the vial
  2. 2. Is the sample in the vial (correct volume, not evaporated)?
    → YES: Continue
    → NO: No sample — re-pipette
  3. 3. Sample stability — prepared >24h ago?
    → YES: Yes → degradation. Re-prepare a fresh sample.
    → NO: Continue
  4. 4. Check the detection wavelength vs the substance λmax
    → YES: Detection at λ does NOT match λmax → no signal. Scan DAD 200-400nm.
    → NO: Continue
  5. 5. Test: inject a pure standard (of known concentration, fresh)
    → YES: The standard gives a peak → problem with the sample (matrix, derivatization)
    → NO: No peak even with the standard → system problem (column, phase, gradient)
⚠️ Common causes:
  • Sample not drawn from the vial (autosampler bug)
  • Sample degraded (>24h pH/temp/light)
  • Detection at the wrong wavelength
  • Wrong mobile phase (e.g. forgotten TFA)
  • Column reversed / wrong stationary phase
  • Substance elutes at the front (V0) → unretained, not visible
✓ Fixes:
  • ✓ Re-prepare a fresh sample per the exact protocol
  • ✓ UV-Vis DAD scan 200-400nm + search for λmax
  • ✓ Check the mobile-phase composition — was TFA added?
  • ✓ Test the reverse column direction (carefully!)
  • ✓ For retention <1 min — lower the % B, MeOH instead of ACN
  • ✓ Check the "expected_rt" table in wp_molgod_hplc_methods
Pressure too high critical

Symptom: Pump pressure > 80% of the column max or system shutdown with a high-pressure error

🔍 Diagnostic tree:
  1. 1. Check that the column is connected correctly (arrow direction)
    → YES: OK
    → NO: Column reversed → flip it (never run it "backwards")
  2. 2. Test: remove the column from the system, run pump+detector alone
    → YES: Pressure drops to <50 bar → problem in the column (clogged)
    → NO: Pressure stays high → in-line filter clogged, frit fouled
  3. 3. Check the pre-column filter (in-line frit)
    → YES: Fouled and brown → replace it
    → NO: Continue
  4. 4. Back-flush the column with 50:50 ACN:H2O without the column — does it disappear?
    → YES: Particles stuck in the first mm — a 30 min flush may recover it
    → NO: Replace the column
⚠️ Common causes:
  • In-line filter (frit) clogged with particles
  • Buffer salting out (precipitation at high %B)
  • Sample contains suspended matter (filter 0.22 µm before injection)
  • Column clogged (column bed compaction)
  • Gradient with a buffer phase + high organic → salt precipitation
✓ Fixes:
  • ✓ ALWAYS filter the sample through 0.22 µm PVDF before injection
  • ✓ Replace the in-line filter every 100 injections (or when pressure rises >20%)
  • ✓ Do NOT use >20mM phosphate buffer + >70% ACN (the salt precipitates)
  • ✓ Flush the column for 30 min with 50:50 ACN:H2O in the reverse direction (when the manufacturer allows it)
  • ✓ Pre-column 4×3mm to protect the main column
Ghost peaks high

Symptom: Unexplained peaks on the chromatogram absent from the calibration

🔍 Diagnostic tree:
  1. 1. Test: blank injection (pure sample solvent)
    → YES: A ghost appears → contamination of the system or eluents
    → NO: Appears only with the sample → matrix
  2. 2. Does the ghost grow with the gradient (elutes at high %B)?
    → YES: Yes → overloaded column or strong-retained from a previous run
    → NO: Independent of the gradient → autosampler carryover
  3. 3. Increase carryover wash (between injections)
    → YES: Helps → carryover was to blame. Use a stronger wash protocol.
    → NO: Continue
  4. 4. Pure water injection — is there a peak?
    → YES: Yes → contamination of the water source (organics from the DI system)
    → NO: Continue
⚠️ Common causes:
  • Carryover in the autosampler needle/loop
  • Eluent contamination (even HPLC-grade)
  • Strong-retained components from previous runs
  • Plastic in the vials (phthalates, PEG from the caps)
  • Insufficiently purified DI water
✓ Fixes:
  • ✓ Strengthen the wash protocol: 100% B → 100% A → 50:50 (3 cycles)
  • ✓ Strong wash: 100% DMSO or 100% MeOH before calibration
  • ✓ Filter the eluents through 0.22 µm PTFE if in doubt
  • ✓ Use amber glass + Teflon-lined caps for samples
  • ✓ Periodic gradient ramp to 100% B for 10 min (clean-out)
📚 Scientific references (Chicago Author-Date) — click to expand
  1. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. John Wiley & Sons. Chapter 17 (Troubleshooting) pp. 559-616. ISBN 978-0-470-16754-0. https://doi.org/10.1002/9780470508183 [link ↗]
  2. Dolan, John W.. 2014. LC Troubleshooting (monthly column 1989-2024). LCGC North America. [link ↗] — John Dolan 35-letnia seria miesięcznych artykułów problemowych
  3. Kromidas, Stavros. 2017. HPLC Made to Measure: A Practical Handbook for Optimization. 2nd ed. Wiley-VCH. ISBN 978-3-527-31377-1. — Praktyczny przewodnik problem-solving dla labs analitycznych
  4. Dolan, John W.. 2013. When to Modify Method Conditions. 192-199. [link ↗] — Decision flow for changing flow rate / temperature / %B vs swapping columns.
  5. Dong, Michael W.. 2019. HPLC and UHPLC for Practicing Scientists. 2nd ed. Wiley. ISBN 978-1-119-31378-3. https://doi.org/10.1002/9781119313793 [link ↗] — Chapter 9 covers troubleshooting modern UHPLC systems (sub-2 µm particles).
  6. Meyer, Veronika R.. 2010. Practical High-Performance Liquid Chromatography. 5th ed. Wiley. ISBN 978-0-470-68218-0. — Solid step-by-step problem isolation chapter (eluents, columns, instruments).
  7. Snyder, L. R., J. J. Kirkland, and J. L. Glajch. 1997. Practical HPLC Method Development. 2nd ed. Wiley. ISBN 978-0-471-00703-6. — Method-development companion volume with troubleshooting cross-refs.
  8. Carr, Peter W.. 2009. The new physical chemistry of HPLC. 1764-1772. https://doi.org/10.1016/j.chroma.2008.11.094 [link ↗] — Theoretical basis for diagnosing efficiency losses (mass-transfer, eddy diffusion).
  9. Heyden, Yvan Vander, et al.. 2009. Robustness of pharmaceutical liquid chromatographic methods. 2120-2129. https://doi.org/10.1016/j.jchromb.2008.10.052 [link ↗] — How to diagnose method failures vs. system failures (Plackett-Burman).
  10. Engelhardt, Heinz. 2014. 100 Years of Chromatography. 2nd ed. Wiley-VCH. ISBN 978-3-527-33473-5. — Historical context for ghost-peak phenomenology (silica chemistry).
  11. Stoll, Dwight R., and Peter W. Carr. 2017. Two-Dimensional Liquid Chromatography: A State of the Art Tutorial. 519-531. https://doi.org/10.1021/acs.analchem.6b03506 [link ↗]
  12. Carr, Peter W.. 2009. The new physical chemistry of HPLC. 1764-1772. https://doi.org/10.1016/j.chroma.2008.11.094 [link ↗]
  13. Wu, Naijun, and Anton M. Clausen. 2007. Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations. 1167-1182. https://doi.org/10.1002/jssc.200700026 [link ↗]
  14. Engelhardt, Heinz. 2014. 100 Years of Chromatography. 2nd ed. Wiley-VCH. ISBN 978-3-527-33473-5.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. Probabilistic approach to peak deconvolution in chromatography. 8525-8531. https://doi.org/10.1021/ac101742z [link ↗]
🧪 Solubility and solvent compatibility MolGod_SOLUB_1
Molecule
Tetrahydrofuran
Formula
C4H8O
logP
0.50
Mass (g/mol)
72.11
Polarity
Moderate

⚠️ HSP estimate (literature / group contribution). Indicative data — does not replace experimental studies.

Solvent Compat. Ra Visual GC-MS HPLC Applications References
Water (H₂O)− Poor35.9
✗ NieA (aqueous) (RP)
buffercell cultureanalyticalhydrophilic extraction
Ethanol (EtOH)− Poor12.0
✗ NieA/B modifier (RP/NP)
extractionspectroscopy (UV-Vis)synthesisHPLC modifier
Methanol (MeOH)− Poor16.1
✗ NieA/B (RP) (RP)
HPLC (eluent)LC-MSKarl FischerUV-transparent do 205 nm
Acetone+ Good5.5
✗ NieB modifier (NP)
GC headspacecrystallizationdegreasingsynthesis
Acetonitrile (ACN)− Poor12.8
✗ NieB (RP) (RP)
HPLC eluent (gold standard)LC-MS (wolny cut-off UV 190 nm)peptide analysis
DMSO− Poor11.4
✗ NieN/A (N/A)
NMR (d6-DMSO)cell biology (cryopreservation)drug deliverysynthesis
THF+ Good0.0
✗ NieB (NP) (NP)
GPC/SEC (polymer analysis)Grignard synthesisorganometallic
DCM (CH₂Cl₂)+ Good3.4
✓ TakB (NP) (NP)
extractionNP-HPLCGC-MScrystallization (anti-solvent)
Chloroform (CHCl₃)+ Good4.0
✓ TakN/A (toxic) (N/A)
NMR (CDCl3)lipid extraction (Folch method)NP-TLC
Hexane~ Avg.10.5
✓ TakA (NP) (NP)
NP-HPLCoil extraction (lipids)GC-MSTLC (NP)
Toluene~ Avg.7.8
✓ TakB (NP) (NP)
NMR (d8-toluene)synthesisDean-Stark azeotropic drying
📚 Scientific references for solvents (Chicago Author-Date) — click to expand

11 solvents × 5 independent scientific sources (NIST/CRC/IARC/Hansen/Reichardt/Smallwood/Wypych/Armarego/Snyder/GESTIS). 55+ full citations below.

Water (H₂O)
  1. NIST — NIST Chemistry WebBook — Water (CAS 7732-18-5)
  2. CRC — CRC Handbook of Chemistry and Physics, 104th ed., Sec. 8 (Properties of Water)
  3. IAPWS — IAPWS Release on Static Dielectric Constant of Water
  4. Reichardt 2011 — Solvents and Solvent Effects in Organic Chemistry
  5. GESTIS — GESTIS Substance Database — Water
Ethanol (EtOH)
  1. NIST — NIST Chemistry WebBook — Ethanol (CAS 64-17-5)
  2. CRC — CRC Handbook — Ethanol physical constants
  3. Snyder & Kirkland — Modern Liquid Chromatography — Ethanol eluotropic
  4. Smallwood — Handbook of Organic Solvent Properties — Ethanol
  5. GESTIS — GESTIS Substance Database — Ethanol
Methanol (MeOH)
  1. NIST — NIST Chemistry WebBook — Methanol (CAS 67-56-1)
  2. CRC — CRC Handbook — Methanol physical constants
  3. Snyder & Kirkland — Modern Liquid Chromatography — MeOH eluotropic, eo=0.95
  4. GESTIS — GESTIS Substance Database — Methanol
Acetone
  1. NIST — NIST Chemistry WebBook — Acetone (CAS 67-64-1)
  2. CRC — CRC Handbook — Acetone physical & thermodynamic constants
  3. Hansen 2007 — Hansen Solubility Parameters — Acetone (dD=15.5, dP=10.4, dH=7.0)
  4. Smallwood — Handbook of Organic Solvent Properties — Acetone
  5. GESTIS — GESTIS Substance Database — Acetone
Acetonitrile (ACN)
  1. NIST — NIST Chemistry WebBook — Acetonitrile (CAS 75-05-8)
  2. CRC — CRC Handbook — Acetonitrile constants
  3. Snyder & Kirkland — Modern Liquid Chromatography — ACN gold-standard HPLC eluent
  4. Reichardt 2011 — Solvents and Solvent Effects — ACN dipolar aprotic
  5. GESTIS — GESTIS Substance Database — Acetonitrile
DMSO
  1. NIST — NIST Chemistry WebBook — DMSO (CAS 67-68-5)
  2. Wypych 2019 — Handbook of Solvents Vol. 1 — DMSO comprehensive properties
  3. Hansen 2007 — HSP — DMSO (dD=18.4, dP=16.4, dH=10.2)
  4. Reichardt 2011 — Solvents and Solvent Effects — DMSO E_T(30)=45.1, dipolar aprotic
  5. GESTIS — GESTIS Substance Database — DMSO
THF
  1. NIST — NIST Chemistry WebBook — THF (CAS 109-99-9)
  2. Armarego 2009 — Purification of Laboratory Chemicals — THF drying & peroxide test
  3. Hansen 2007 — Hansen Solubility Parameters — THF (dD=16.8, dP=5.7, dH=8.0)
  4. Smallwood — Handbook of Organic Solvent Properties — THF
  5. GESTIS — GESTIS Substance Database — Tetrahydrofuran
DCM (CH₂Cl₂)
  1. NIST — NIST Chemistry WebBook — Dichloromethane (CAS 75-09-2)
  2. IARC 71 — IARC Monograph 71 — DCM (Group 2A carcinogen)
  3. Hansen 2007 — Hansen Solubility Parameters — DCM (dD=18.2, dP=6.3, dH=6.1)
  4. Reichardt 2011 — Solvents and Solvent Effects — DCM polarity index
  5. GESTIS — GESTIS Substance Database — Dichloromethane
Chloroform (CHCl₃)
  1. NIST — NIST Chemistry WebBook — Chloroform (CAS 67-66-3)
  2. IARC 73 — IARC Monograph 73 — Chloroform (Group 2B carcinogen)
  3. Hansen 2007 — Hansen Solubility Parameters — CHCl3 (dD=17.8, dP=3.1, dH=5.7)
  4. Reichardt 2011 — Solvents and Solvent Effects — CHCl3 H-bond donor strength
  5. GESTIS — GESTIS Substance Database — Chloroform
n-Hexane
  1. NIST — NIST Chemistry WebBook — n-Hexane (CAS 110-54-3)
  2. ATSDR n-Hexane — ATSDR Toxicological Profile for n-Hexane — neuropatia obwodowa (n-Heksan NIE jest kancerogenem IARC)
  3. Hansen 2007 — Hansen Solubility Parameters — n-Hexane (dD=14.9, dP=0, dH=0)
  4. Snyder & Kirkland — Modern Liquid Chromatography — n-Hexane NP standard, eo=0.00
  5. GESTIS — GESTIS Substance Database — n-Hexane
Toluene
  1. NIST — NIST Chemistry WebBook — Toluene (CAS 108-88-3)
  2. IARC 71 — IARC Monograph 71 — Toluene
  3. Hansen 2007 — Hansen Solubility Parameters — Toluene (dD=18.0, dP=1.4, dH=2.0)
  4. Smallwood — Handbook of Organic Solvent Properties — Toluene
  5. GESTIS — GESTIS Substance Database — Toluene
Solubility theory (applied in compatibility prediction):
  1. Yalkowsky, Samuel H., and Shri C. Valvani. 1980. "Solubility and Partitioning I: Solubility of Nonelectrolytes in Water." Journal of Pharmaceutical Sciences 69 (8): 912–922. https://doi.org/10.1002/jps.2600690814 — General Solubility Equation (GSE): logS = 0.5 − logP − 0.01(MP−25).
  2. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook. 2nd ed. CRC Press. https://doi.org/10.1201/9781420006834 — HSP triplet (dD, dP, dH) + Ra formula.
  3. Stefanis, E., and C. Panayiotou. 2008. "Prediction of Hansen Solubility Parameters with a New Group-Contribution Method." Int J Thermophys 29: 568–585. https://doi.org/10.1007/s10765-008-0415-z
  4. Reichardt, Christian, and Thomas Welton. 2011. Solvents and Solvent Effects in Organic Chemistry. 4th ed. Wiley-VCH. https://doi.org/10.1002/9783527632220 — E_T(30) polarity scale, solwatochromia.
  5. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. Introduction to Modern Liquid Chromatography. 3rd ed. Wiley. https://doi.org/10.1002/9780470508183 — Eluotropic series, polarity index.
  6. Van Krevelen, D. W., and K. Te Nijenhuis. 2009. Properties of Polymers. 4th ed. Elsevier. https://doi.org/10.1016/B978-0-08-054819-7.X0001-5 — Hoftyzer–Van Krevelen group contribution dla dD/dP/dH z SMILES.
  7. Marcus, Yizhak. 1998. The Properties of Solvents. Wiley Series in Solution Chemistry, Vol. 4. ISBN 9780471983699 — Complete tabular set of 250+ solvents (ε, μ, donicity, acceptor numbers).
  8. PubChem Compound Database — CAS 109-99-9 lookup ↗ — logP (XLogP3), water solubility experimental + predicted.

Full bibliography in the REFERENCES accordion (at the bottom of the page) — Chicago Manual of Style 17th ed., Author-Date.

📚 Technical FAQ — Tetrahydrofuran (5) MolGod_TECHFAQ_1
❓ Jak przygotować roztwór standardowy THF o stężeniu 0.1 M?
Aby przygotować roztwór standardowy tetrahydrofuranu (THF) o stężeniu 0.1 M, należy obliczyć masę substancji potrzebną do rozpuszczenia w określonej objętości rozpuszczalnika. Masa molowa THF wynosi 72.11 g/mol. Dla roztworu 0.1 M w 1 litrze (1000 ml) potrzeba: masa = stężenie × objętość × masa molowa = 0.1 mol/L × 1 L × 72.11 g/mol = 7.211 g THF. Rozpuszczalnik należy odważyć dokładnie i rozpuścić w odpowiednim rozpuszczalniku, np. etanolu lub heksanie, a następnie uzupełnić do 1 litra.
Helpful?
❓ Jak przechowywać THF, aby zachować jego stabilność?
THF należy przechowywać w szczelnie zamkniętych butelkach z ciemnego szkła lub tworzywa sztucznego odpornego na rozpuszczalniki organiczne. Optymalna temperatura przechowywania to 15-25°C, z dala od bezpośredniego światła słonecznego i źródeł ciepła. Wilgotność względna powietrza powinna być niska, aby uniknąć absorpcji wody przez THF. Butelki należy przechowywać pionowo, aby zminimalizować kontakt z powietrzem.
Helpful?
❓ Jaka metoda analityczna jest odpowiednia do analizy czystości THF?
Do analizy czystości THF można zastosować chromatografię gazową (GC) lub wysokosprawną chromatografię cieczową (HPLC). Ze względu na niską masę molową (72.11 g/mol) i polarny charakter (logP nieznany, ale THF jest rozpuszczalnikiem aprotycznym), GC jest często preferowana. Kolumna kapilarna z fazą stacjonarną o odpowiedniej polarności pozwoli na rozdzielenie ewentualnych zanieczyszczeń. Alternatywnie, HPLC z odpowiednim detektorem (np. UV) może być użyteczna, jeśli THF jest mieszaniną z innymi związkami o podobnej polarności.
Helpful?
❓ Jakie są potencjalne niezgodności chemiczne THF z innymi substancjami?
THF może reagować z silnymi utleniaczami (np. nadmanganianem potasu) lub związkami zawierającymi metale przejściowe, które mogą katalizować jego rozkład. Ponadto, THF może tworzyć niepożądane mieszaniny azeotropowe z niektórymi rozpuszczalnikami, np. etanolem. Należy unikać kontaktu THF z silnymi kwasami lub zasadami, które mogą prowadzić do niekontrolowanych reakcji. Przed użyciem w reakcjach należy sprawdzić zgodność z innymi składnikami.
Helpful?
❓ W jakich praktycznych zastosowaniach laboratoryjnych wykorzystuje się THF?
THF jest powszechnie stosowany jako rozpuszczalnik w syntezie organicznej, np. do rozpuszczania estrów, ketonów i soli metali przejściowych. Jest również używany jako medium reakcyjne w reakcjach polimeryzacji, np. w produkcji poliuretanów. THF jest także stosowany do ekstrakcji związków organicznych oraz jako rozpuszczalnik w chromatografii preparatywnej. Jego niska temperatura wrzenia (66.2°C) i dobra rozpuszczalność dla wielu związków organicznych czynią go wszechstronnym odczynnikiem laboratoryjnym.
Helpful?
🧮 Laboratory calculators (8) MolGod_LABCALC_1
Dilution (C₁V₁=C₂V₂)
Molarity (M=n/V)
pH Buffer (Henderson-Hasselbalch)
Beer-Lambert (A=εcl)
Mass → Moles
Concentration % → M
ppm → mg/L
Temperature C↔F↔K

Verified formulas: IUPAC Gold Book ↗, DOI ↗

📊 Spectroscopic Databases MolGod_SPECDB_3
📋 Laboratory protocol generator MolGod_PROTOCOL_1

Protocol generated based on: GHS SDS, Aldrich Lab Guide ↗

🏷️ Label generator (QR) MolGod_LABEL_1
Tetrahydrofuran• TETRAHYDROFURAN / Oxolane• CAS: 109-99-9• Formula: C4H8O• Mass: 72.11 g/molDANGERGHS HAZARD STATEMENTS:H225: Highly flammable liquid and vapourH351: Suspected of causing cancerH335: May cause respiratory irritationH319: Causes serious eye irritationDH ScientificScience first. Commerce as consequence.Batch No.: Netto Mass: MFG:
🧪 Solution preparation assistant (Smart Prep) MolGod_PREP_2

Enter what you want to prepare — I'll generate an SOP

Examples below — click to insert:
Preset recipes:
📚 Scientific literature overview — CAS 109-99-9MolGod_LITHUB_MAIN
⭐ Key findings (scientific literature) 20 publications
🏆 CAS 109-99-9 — multi-criteria ranking (W12): 30% citations · 20% recency · 20% topic · 15% historical · 15% open access.
  1. #1
    Joshua J. W. Roan; Zohaib Siddiqi; Brooks A. Abel (2026) · Journal of the American Chemical Society
    Why it matters: Recent (2026) · open access
    SCORE 9.66 Mechanism Citations: 3 Open Access DOI ↗ PubMed ↗
  2. #2
    et al. (2025) · International Journal of Molecular Sciences
    Why it matters: Recent (2025) · open access
    SCORE 8.58 Mechanism Citations: 5 Open Access DOI ↗ PubMed ↗
  3. #3
    et al. (2026) · Materials
    Why it matters: Recent (2026) · open access
    SCORE 7.85 Industrial Open Access DOI ↗ PubMed ↗
  4. #4
    et al. (2025) · ACS Omega
    Why it matters: Recent (2025) · open access
    SCORE 7.85 Mechanism Open Access DOI ↗ PubMed ↗
  5. #5
    et al. (2025) · Angewandte Chemie International Edition
    Why it matters: Recent (2025)
    SCORE 7.3 Mechanism Citations: 1 DOI ↗ PubMed ↗
  6. #6
    et al. (2026) · Angewandte Chemie International Edition
    Why it matters: Recent (2026) · open access
    SCORE 7.05 Mechanism Open Access DOI ↗ PubMed ↗
  7. #7
    et al. (2026) · ACS Omega
    Why it matters: Recent (2026) · open access
    SCORE 7.05 Mechanism Open Access DOI ↗ PubMed ↗
  8. #8
    et al. (2026) · The Journal of Chemical Physics
    Why it matters: Recent (2026) · open access
    SCORE 7.05 Mechanism Open Access DOI ↗ PubMed ↗
  9. #9
    Yiou Mei; Yunfei Du (2025) · ChemMedChem
    Why it matters: Recent (2025)
    SCORE 6.5 Mechanism Citations: 1 DOI ↗ PubMed ↗
  10. #10
    Hartwig, Andrea; https://orcid.org/, Arand, Michael; https://orcid.org/, MAK Commission (2024) · German Medical Science
    Why it matters: Recent (2024) · open access
    SCORE 6.25 Mechanism Open Access DOI ↗
  11. #11
    Fernández-Peña L, Díez-Poza C, González-Andrés P et al. (2022) · Marine drugs
    Why it matters: Review · open access
    SCORE 5.85 Review Open Access DOI ↗ PubMed ↗
  12. #12
    Fowles J; Boatman R; Bootman J et al. (2013) · Critical reviews in toxicology
    Why it matters: Must-cite (canon) · review
    SCORE 5.74 Review MUST-CITE Citations: 40 DOI ↗
  13. #13
    et al. (2026) · Journal of Chromatography A
    Why it matters: Recent (2026)
    SCORE 5.6 Analytics DOI ↗ PubMed ↗
  14. #14
    J. Derouault, P. Granger, M. T. Forel (1977) · Inorganic Chemistry
    Why it matters: Selected by multi-criteria score (citations + recency + topic + historical + OA).
    SCORE 5.24 Analytics Citations: 55 DOI ↗
  15. #15
    et al. (2025) · Microchimica Acta
    Why it matters: Recent (2025)
    SCORE 4.9 Mechanism Citations: 1 DOI ↗ PubMed ↗
  16. #16
    et al. (2025) · Organic Letters
    Why it matters: Recent (2025)
    SCORE 4.8 Mechanism DOI ↗ PubMed ↗
  17. #17
    Shin-Jowl Tan, Ward T. Robinson, Kanki Komiyama et al. (2011) · Tetrahedron
    Why it matters: Selected by multi-criteria score (citations + recency + topic + historical + OA).
    SCORE 4.54 Mechanism Citations: 25 DOI ↗
  18. #18
    Hongjun Yang, Shuanshi Fan, Xuemei Lang et al. (2011) · Journal of Chemical & Engineering Data
    Why it matters: Selected by multi-criteria score (citations + recency + topic + historical + OA).
    SCORE 4.27 Mechanism Citations: 20 DOI ↗
  19. #19
    et al. (2026) · The Journal of Chemical Physics
    Why it matters: Recent (2026)
    SCORE 4 Mechanism DOI ↗ PubMed ↗
  20. #20
    et al. (2025) · Chemical Communications
    Why it matters: Recent (2025)
    SCORE 4 Mechanism DOI ↗ PubMed ↗
📈 HPLC gradient — optimizer (LSS) TEMPLATE

Gradient based on PubChem XLogP3 + LSS (Snyder et al. 2010, ch. 9).

  • Column: C18
  • Buffer: phosphate
  • Flow: 1 mL/min
  • logP: 0.5 (PubChem XLogP3)
  • Ramp: 9% → 95% B, 10 min
  • Total analysis time: 23 min
t (min) %A %B flow (mL/min) Comment
0 91 9 1 start (equilibrium)
2 91 9 1 end of initial hold
12 5 95 1 end of LSS ramp
17 5 95 1 column wash
18 91 9 1 return to init
23 91 9 1 re-equilibration
📚 Scientific references (Chicago Author-Date)
  1. Snyder, Lloyd R., John W. Dolan, and Joseph J. Kirkland. 2010. Introduction to Modern Liquid Chromatography. Wiley. — Chapter 9 — gradient elution, LSS theory (cited as Snyder et al. 2010 in tool description).
  2. Schoenmakers, Peter J. 1986. Optimization of Chromatographic Selectivity: A Guide to Method Development. Elsevier. — Numerical optimization of gradient programs.
  3. Snyder, L. R., and J. W. Dolan. 2007. High-Performance Gradient Elution: The Practical Application of the Linear-Solvent-Strength Model. Wiley. — Foundational LSS reference for the %B_init = 5 + 8·logP heuristic implemented here.
  4. Nikitas, Pavlos, and Adrian Pappa-Louisi. 2009. "Retention models for isocratic and gradient elution in reversed-phase liquid chromatography." Journal of Chromatography A 1216: 1737-1755. [DOI ↗] — Modern review of gradient retention models — basis for non-LSS extensions.
  5. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772. [DOI ↗]
  6. Dong, Michael W. 2019. HPLC and UHPLC for Practicing Scientists. Wiley. https://doi.org/10.1002/9781119313793. — Modern UHPLC gradient programming, sub-2 µm scaling rules.
  7. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations." Journal of Separation Science 30: 1167-1182. [DOI ↗]
  8. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531. [DOI ↗] — Reference for orthogonal gradient design (2D-LC second dimension).
  9. Dolan, John W.. 2013. "When to Modify Method Conditions." LCGC North America 31: 192-199.
  10. Meyer, Veronika R. 2010. Practical High-Performance Liquid Chromatography. Wiley. — Chapter 7 — practical gradient design with isokratyczny scouting.
  11. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531. [DOI ↗]
  12. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772. [DOI ↗]
  13. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations." Journal of Separation Science 30: 1167-1182. [DOI ↗]
  14. Engelhardt, Heinz. 2014. 100 Years of Chromatography. Wiley-VCH.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531. [DOI ↗]

REST: /wp-json/molgod/v1/hplc/gradient/109-99-9

🌈 Detector + wavelength (UV/Vis) 220 nm
CompoundTetrahydrofuran (UV cutoff)
λmax220 nm
λmin—
εmax (M⁻¹·cm⁻¹)—
Solvent (reference)self
Suggested λ220 nm
Recommended detectorELSD
AlternativesRID, MS, CAD

Data source: Sadek 2002 HPLC Solvent Guide (UV cutoff)

⚠ Mobile phase compatibility

  • warning λ=220 nm near cutoff Tetrahydrofuran (THF) (220 nm) — possible baseline noise and drift; use higher-purity reagents.
  • warning λ=220 nm near cutoff Diethyl ether (218 nm) — possible baseline noise and drift; use higher-purity reagents.
  • critical λ=220 nm < UV cutoff Dichloromethane (232 nm) — solvent absorbs; measurement not possible.
  • critical λ=220 nm < UV cutoff Acetic acid (1%) (230 nm) — solvent absorbs; measurement not possible.
📚 Scientific references (Chicago Author-Date) 26 refs · 2 baz

METODA Method Bibliography

  1. Skoog, Douglas A., F. James Holler, and Stanley R. Crouch. 2017. "Principles of Instrumental Analysis." 7th ed. Cengage Learning. ISBN 978-1-305-57721-3.
  2. Perkampus, Heinz-Helmut. 1992. "UV-VIS Spectroscopy and Its Applications." Springer. ISBN 978-3-642-77479-9. →
  3. Sadek, Paul C.. 2002. "The HPLC Solvent Guide." 2nd ed. Wiley-Interscience. ISBN 978-0-471-41138-4.
  4. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. "Introduction to Modern Liquid Chromatography." 3rd ed. Wiley. ISBN 978-0-470-16754-0. →
  5. Dong, Michael W.. 2019. "HPLC and UHPLC for Practicing Scientists." 2nd ed. Wiley. ISBN 978-1-119-31378-3. →
  6. Meyer, Veronika R.. 2010. "Practical High-Performance Liquid Chromatography." 5th ed. Wiley. ISBN 978-0-470-68218-0.
  7. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531 →
  8. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531 →
  9. Kazakevich, Yuri V., and Rosario LoBrutto, eds.. 2007. "HPLC for Pharmaceutical Scientists." Wiley-Interscience. ISBN 978-0-471-68162-4. →
  10. Kim, Sunghwan, et al.. 2023. "PubChem 2023 update." Nucleic Acids Research 51: D1373-D1380 →
  11. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531 →
  12. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772 →
  13. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations." Journal of Separation Science 30: 1167-1182 →
  14. Engelhardt, Heinz. 2014. "100 Years of Chromatography." 2nd ed. Wiley-VCH. ISBN 978-3-527-33473-5.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531 →

MOLEKUŁA Per-CAS bibliography (live from 13+ databases)

Sources: db:europepmc (9)

  1. db:europepmc Wang, C; Rishi, K; Ku, BK; Kulkarni, P. 2026. "Compatibility of engineered stone materials with tetrahydrofuran processing for crystalline silica analysis by XRD." Annals of work exposures and health. https://doi.org/10.1093/annweh/wxaf052. →
  2. db:europepmc Yu, J; Qu, A; Ju, Z; Liu, N. 2026. "Toward Deep Dehydration of Tetrahydrofuran: Preparation and Application of a Microporous/Mesoporous Composite Adsorbent." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c01103. →
  3. db:europepmc Boullier, C; Gavelle, S; Lhoste, J; Henrion, S. 2026. "Access to Regiodefined Tetrahydrofuran-3-one-Derived C-2 Silyl Enol Ethers from α-Triisopropylsilyl-α-diazoketones: The TIPS Trick." Organic letters. https://doi.org/10.1021/acs.orglett.6c00147. →
  4. db:europepmc Geng, S; Wang, T; Kong, Q; Ouyang, D. 2026. "Skeletal editing of tetrahydrofurans to pyrrolidines through O-to-N single atom swap." Nature communications. https://doi.org/10.1038/s41467-026-71886-y. →
  5. db:europepmc Duda, DP; Sprouse, S; Hu, Y; Wiedner, ES. 2026. "Redox Potentials for Hydrogen Species in Acetonitrile and Tetrahydrofuran." The journal of physical chemistry. A. https://doi.org/10.1021/acs.jpca.6c00629. →
  6. db:europepmc Hashii, T; Tanigaki, H; Furukawa, T; Kowada, H. 2026. "Liquid-Phase Synthesis of Lithium Argyrodite Sulfide Electrolytes Using Tetrahydrofuran and Water." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.5c06765. →
  7. db:europepmc Han, F; Zheng, C; Xue, S; Li, X. 2026. "Effects of Pore Structure on Methane Adsorption and Diffusion Properties in Varying-Rank Coals Modified by Tetrahydrofuran." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c00630. →
  8. db:europepmc Wang, L; Liu, R; Yu, Z; Hou, CJ. 2026. "Bisaspochalasin F: a tetrahydrofuran ring-fused cytochalasan homodimer from an endophytic <i>Aspergillus flavipes</i> as a Ca<sub>v</sub>3.2 inhibitor." Organic & biomolecular chemistry. https://doi.org/10.1039/d6ob00028b. →
  9. db:europepmc Thongsawas, N; Katheng, A; Kengtanyakich, S; Lekatana, H. 2026. "Effects of Isopropyl Alcohol, Tetrahydrofuran, Pyridine, and Acetonitrile on Surface Roughness, Surface Morphology, and Shear Bond Strength Between Composite Resin and Different Provisional Restorative Materials." Dentistry journal. https://doi.org/10.3390/dj14050309. →

REST: /wp-json/molgod/v1/hplc/detector/109-99-9

📐 HPLC peak symmetry calculator (USP Tf / As)

Calculate the USP tailing factor (Tf) and asymmetry (As) from the peak half-widths. Enter a (left half-width) and b (right half-width) measured at 5% or 10% of peak height.

📚 References (Chicago Author-Date)
  1. USP General Chapter <621>. 2024. "Chromatography." United States Pharmacopeial Convention. [link ↗] — Defines USP Tailing Factor T = (a+b)/(2a) measured at 5% peak height.
  2. International Council for Harmonisation (ICH). 2023. "Validation of Analytical Procedures Q2(R2)." ICH Expert Working Group. [link ↗] — Tailing factor is a system suitability parameter (Section 6).
  3. Foley, Joe P., and John G. Dorsey. 1983. "Equations for calculation of chromatographic figures of merit for ideal and skewed peaks." Analytical Chemistry 55: 730-737 https://doi.org/10.1021/ac00255a033 [link ↗] — Original asymmetry factor As = b/a at 10% height (Foley & Dorsey 1983).
  4. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. "Introduction to Modern Liquid Chromatography." Wiley. https://doi.org/10.1002/9780470508183 [link ↗] — Chapter 2.4 — peak shape diagnostics and remedies.
  5. Dolan, John W.. 2003. "Peak tailing and resolution." LCGC North America 21: 610-614 [link ↗] — How tailing factor degrades effective resolution.
  6. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531 https://doi.org/10.1021/ac101742z [link ↗] — Modern numerical deconvolution for asymmetric peaks.
  7. Kromidas, Stavros. 2017. "HPLC Made to Measure: A Practical Handbook for Optimization." Wiley-VCH. — Practical Tf and As thresholds for routine QC.
  8. Dong, Michael W.. 2019. "HPLC and UHPLC for Practicing Scientists." Wiley. https://doi.org/10.1002/9781119313793 [link ↗]
  9. Meyer, Veronika R.. 2010. "Practical High-Performance Liquid Chromatography." Wiley.
  10. Heyden, Yvan Vander, et al.. 2009. "Robustness of pharmaceutical liquid chromatographic methods." Journal of Chromatography B 877: 2120-2129 https://doi.org/10.1016/j.jchromb.2008.10.052 [link ↗]
  11. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531 https://doi.org/10.1021/acs.analchem.6b03506 [link ↗]
  12. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772 https://doi.org/10.1016/j.chroma.2008.11.094 [link ↗]
  13. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations." Journal of Separation Science 30: 1167-1182 https://doi.org/10.1002/jssc.200700026 [link ↗]
  14. Engelhardt, Heinz. 2014. "100 Years of Chromatography." Wiley-VCH.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531 https://doi.org/10.1021/ac101742z [link ↗]
📊 Resolution and plate count calculator (Rs, N, H)

Calculate the resolution Rs, the number of theoretical plates N and HETP (H) for a pair of HPLC peaks. Enter the retention times, peak widths (at 50% or at the base) and the column length.

📚 References (Chicago Author-Date)
  1. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. "Introduction to Modern Liquid Chromatography." 3rd ed. John Wiley & Sons. ISBN 978-0-470-16754-0. https://doi.org/10.1002/9780470508183 [link ↗] — Chapter 2 covers resolution, plate count and HETP fundamentals (Snyder et al. 2010).
  2. USP General Chapter <621>. 2024. "Chromatography." USP-NF 2024 ed. United States Pharmacopeial Convention. [link ↗] — Defines Rs >= 1.5 acceptance criterion and N calculation methods.
  3. Dolan, John W.. 2003. "How much resolution is enough?." LCGC North America 21: 350-353 [link ↗] — Practical guidance on Rs targets for routine method development.
  4. Van Deemter, J. J., F. J. Zuiderweg, and A. Klinkenberg. 1956. "Longitudinal diffusion and resistance to mass transfer as causes of nonideality in chromatography." Chemical Engineering Science 5: 271-289 https://doi.org/10.1016/0009-2509(56)80003-1 [link ↗] — Origin of N = 5.54·(tr/w0.5)² half-height plate count formulation.
  5. Giddings, J. Calvin. 1965. "Dynamics of Chromatography, Part I: Principles and Theory." Marcel Dekker. ISBN 978-0-8247-1357-7. — Resolution equation Rs = (1/4)·√N·(α-1)/α·k/(1+k) (master equation).
  6. Foley, Joe P., and John G. Dorsey. 1983. "Equations for calculation of chromatographic figures of merit for ideal and skewed peaks." Analytical Chemistry 55: 730-737 https://doi.org/10.1021/ac00255a033 [link ↗] — Skewed-peak corrections to apparent N.
  7. Knox, John H.. 1977. "Practical aspects of LC theory." Journal of Chromatographic Science 15: 352-364 https://doi.org/10.1093/chromsci/15.9.352 [link ↗]
  8. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772 https://doi.org/10.1016/j.chroma.2008.11.094 [link ↗]
  9. Dong, Michael W.. 2019. "HPLC and UHPLC for Practicing Scientists." 2nd ed. Wiley. ISBN 978-1-119-31378-3. https://doi.org/10.1002/9781119313793 [link ↗]
  10. Meyer, Veronika R.. 2010. "Practical High-Performance Liquid Chromatography." 5th ed. Wiley. ISBN 978-0-470-68218-0.
  11. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial." Analytical Chemistry 89: 519-531 https://doi.org/10.1021/acs.analchem.6b03506 [link ↗]
  12. Carr, Peter W.. 2009. "The new physical chemistry of HPLC." Journal of Chromatography A 1216: 1764-1772 https://doi.org/10.1016/j.chroma.2008.11.094 [link ↗]
  13. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations." Journal of Separation Science 30: 1167-1182 https://doi.org/10.1002/jssc.200700026 [link ↗]
  14. Engelhardt, Heinz. 2014. "100 Years of Chromatography." 2nd ed. Wiley-VCH. ISBN 978-3-527-33473-5.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography." Analytical Chemistry 82: 8525-8531 https://doi.org/10.1021/ac101742z [link ↗]

Related products

🧪 System Suitability — live calculator (USP <621>)

Enter data from 5–6 injections (areas, tR, tailing, plates) — the calculator computes %RSD and means and checks compliance with USP <621>. You can paste CSV (comma-separated) or edit individual values.

📚 References (Chicago Author-Date)
  1. USP General Chapter <621>. 2024. "Chromatography (System Suitability section)." USP-NF 2024 ed. United States Pharmacopeial Convention. [link ↗] — Defines RSD area < 2%, tailing < 2.0, N > 2000 acceptance criteria.
  2. International Council for Harmonisation (ICH). 2023. "Validation of Analytical Procedures Q2(R2)." ICH Expert Working Group. [link ↗] — Section 5.4 — system suitability is part of method validation.
  3. US Food and Drug Administration (FDA). 2018. "Reviewer Guidance: Validation of Chromatographic Methods." US Food and Drug Administration. [link ↗] — CDER reviewer perspective on chromatographic validation expectations.
  4. Snyder, Lloyd R., Joseph J. Kirkland, and John W. Dolan. 2010. "Introduction to Modern Liquid Chromatography." 3rd ed. Wiley. — Chapter 2 — system suitability fundamentals (RSD, Tf, N).
  5. Heyden, Yvan Vander, et al.. 2009. "Robustness of pharmaceutical liquid chromatographic methods." — Robustness vs. system suitability — design-of-experiments framework.
  6. Rozet, Eric, et al.. 2013. "Analysis of recent pharmaceutical regulatory documents on analytical method validation."
  7. European Medicines Agency (EMA). 2011. "Guideline on bioanalytical method validation EMEA/CHMP/EWP/192217/2009." EMA. [link ↗] — EMA companion guideline with bioanalytical SS criteria.
  8. Dong, Michael W.. 2019. "HPLC and UHPLC for Practicing Scientists." 2nd ed. Wiley. — UHPLC-specific suitability adjustments (n=5 vs. n=6).
  9. Kazakevich, Yuri V., and Rosario LoBrutto, eds.. 2007. "HPLC for Pharmaceutical Scientists." Wiley-Interscience.
  10. AOAC International. 2016. "Appendix F: Guidelines for Standard Method Performance Requirements." AOAC INTERNATIONAL. [link ↗] — Alternative SS thresholds for food/dietary samples.
  11. Stoll, Dwight R., and Peter W. Carr. 2017. "Two-Dimensional Liquid Chromatography: A State of the Art Tutorial."
  12. Carr, Peter W.. 2009. "The new physical chemistry of HPLC."
  13. Wu, Naijun, and Anton M. Clausen. 2007. "Fundamental and practical aspects of ultrahigh pressure liquid chromatography for fast separations."
  14. Engelhardt, Heinz. 2014. "100 Years of Chromatography." 2nd ed. Wiley-VCH.
  15. Vivó-Truyols, Gabriel, and Hans-Gerd Janssen. 2010. "Probabilistic approach to peak deconvolution in chromatography."

Inne produkty z tej kategorii

📈 UV-VIS spectrum predictor (200-400 nm) λmax 220 nm MolGod_UVVIS_1
0%25%50%75%100%200250300350400220 nmA = ε·c·lA / Aₘₐₓ (%)
CompoundTetrahydrofuran (UV cutoff)
λmax220 nm
λmin—
εmax (M⁻¹·cm⁻¹)—
Solvent (query)water
Solvent (reference)self
Concentration (M)1e-4
Path length (cm)1
Curve FWHM30 nm

Model: Gaussian curve centered at λmax, scaled with the Beer-Lambert law A = ε · c · l. Transmittance T = 10^(-A) · 100%.

📚 Scientific references (Chicago Author-Date)
  1. Wang, C; Rishi, K; Ku, BK; Kulkarni, P. 2026. "Compatibility of engineered stone materials with tetrahydrofuran processing for crystalline silica analysis by XRD." Annals of work exposures and health. https://doi.org/10.1093/annweh/wxaf052. [DOI]
  2. Yu, J; Qu, A; Ju, Z; Liu, N. 2026. "Toward Deep Dehydration of Tetrahydrofuran: Preparation and Application of a Microporous/Mesoporous Composite Adsorbent." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c01103. [DOI]
  3. Boullier, C; Gavelle, S; Lhoste, J; Henrion, S. 2026. "Access to Regiodefined Tetrahydrofuran-3-one-Derived C-2 Silyl Enol Ethers from α-Triisopropylsilyl-α-diazoketones: The TIPS Trick." Organic letters. https://doi.org/10.1021/acs.orglett.6c00147. [DOI]
  4. Geng, S; Wang, T; Kong, Q; Ouyang, D. 2026. "Skeletal editing of tetrahydrofurans to pyrrolidines through O-to-N single atom swap." Nature communications. https://doi.org/10.1038/s41467-026-71886-y. [DOI]
  5. Duda, DP; Sprouse, S; Hu, Y; Wiedner, ES. 2026. "Redox Potentials for Hydrogen Species in Acetonitrile and Tetrahydrofuran." The journal of physical chemistry. A. https://doi.org/10.1021/acs.jpca.6c00629. [DOI]
  6. Hashii, T; Tanigaki, H; Furukawa, T; Kowada, H. 2026. "Liquid-Phase Synthesis of Lithium Argyrodite Sulfide Electrolytes Using Tetrahydrofuran and Water." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.5c06765. [DOI]
  7. Han, F; Zheng, C; Xue, S; Li, X. 2026. "Effects of Pore Structure on Methane Adsorption and Diffusion Properties in Varying-Rank Coals Modified by Tetrahydrofuran." Langmuir : the ACS journal of surfaces and colloids. https://doi.org/10.1021/acs.langmuir.6c00630. [DOI]
  8. Wang, L; Liu, R; Yu, Z; Hou, CJ. 2026. "Bisaspochalasin F: a tetrahydrofuran ring-fused cytochalasan homodimer from an endophytic <i>Aspergillus flavipes</i> as a Ca<sub>v</sub>3.2 inhibitor." Organic & biomolecular chemistry. https://doi.org/10.1039/d6ob00028b. [DOI]
  9. Thongsawas, N; Katheng, A; Kengtanyakich, S; Lekatana, H. 2026. "Effects of Isopropyl Alcohol, Tetrahydrofuran, Pyridine, and Acetonitrile on Surface Roughness, Surface Morphology, and Shear Bond Strength Between Composite Resin and Different Provisional Restorative Materials." Dentistry journal. https://doi.org/10.3390/dj14050309. [DOI]
  10. Linstrom, Peter J., and William G. Mallard, eds. 2023. NIST Chemistry WebBook, NIST Standard Reference Database Number 69. Gaithersburg, MD: National Institute of Standards and Technology. [DOI]
  11. Mayerhöfer, Thomas G., Samir Pahlow, and Jürgen Popp. 2020. "The Bouguer-Beer-Lambert Law: Shining Light on the Obscure." ChemPhysChem 21 (18): 2029-2046. [DOI]
  12. Skoog, Douglas A., F. James Holler, and Stanley R. Crouch. 2017. Principles of Instrumental Analysis. 7th ed. Boston: Cengage Learning. ISBN 978-1-305-57721-3.
  13. Lindon, John C., George E. Tranter, and David W. Koppenaal, eds. 2017. "Encyclopedia of Spectroscopy and Spectrometry." 3rd ed. Amsterdam: Academic Press. ISBN 978-0-12-803224-4.
  14. Field, Leslie D., Sev Sternhell, and John R. Kalman. 2013. "Organic Structures from Spectra." 5th ed. Chichester: Wiley. ISBN 978-1-119-96582-6.
  15. Reusch, William. 2013. "Virtual Textbook of Organic Chemistry: Spectroscopy." East Lansing, MI: Michigan State University.
  16. Lampman, Gary M., Donald L. Pavia, George S. Kriz, and James R. Vyvyan. 2010. "Spectroscopy." 4th ed. Belmont, CA: Cengage Learning. ISBN 978-0-495-88992-9.
  17. Kalsi, P. S. 2010. "Spectroscopy of Organic Compounds." 6th ed. New Delhi: New Age International. ISBN 978-81-224-2032-9.
  18. Williams, Dudley H., and Ian Fleming. 2008. "Spectroscopic Methods in Organic Chemistry." 6th ed. London: McGraw-Hill. ISBN 978-0-07-711559-0.
  19. Sadek, Paul C. 2002. The HPLC Solvent Guide. 2nd ed. Hoboken: Wiley. ISBN 978-0-471-41242-2.
  20. Banwell, Colin N., and Elaine M. McCash. 1994. "Fundamentals of Molecular Spectroscopy." 4th ed. London: McGraw-Hill. ISBN 978-0-07-707976-1.
  21. Perkampus, Heinz-Helmut. 1992. UV-VIS Spectroscopy and Its Applications. Berlin: Springer. https://doi.org/10.1007/978-3-642-77479-9.
  22. Fieser, Louis F. 1949. "Extension of Woodward's Rules for Prediction of Conjugated Diene Absorption." Journal of the American Chemical Society 71 (5): 1854-1857. [DOI]
  23. Woodward, Robert B. 1942. "Structure and the Absorption Spectra of Alpha,Beta-Unsaturated Ketones." Journal of the American Chemical Society 64 (1): 72-75. [DOI]
  24. Beer, August. 1852. "Bestimmung der Absorption des rothen Lichts in farbigen Flüssigkeiten." Annalen der Physik und Chemie 86: 78-88. https://doi.org/10.1002/andp.18521620505.
  25. Lambert, Johann Heinrich. 1760. Photometria. Augsburg: Sumptibus Vidae.
🔍 Confirmation by independent sources SINGLE λmax = 225 nm (1 sources, ±5 nm)
  • 🗃️ database Kim, Sunghwan, et al. 2023. "PubChem 2023 update." Nucleic Acids Research 51 (D1): D1373-D1380. https://doi.org/10.1093/nar/gkac956. UV spectrum data for CAS 109-99-9 sourced from Hazardous Substances Data Bank (HSDB). PubChem CID: 8028. Accessed 2026. λ=225 nm
  • 🔬 peer-reviewed Silvestre, Marialice P.C., Dauphin, Chantal, Hamon, Michel. 1993. "Application of UV absorbance and second-derivative spectrophotometry for analysing casein hydrolysates." Analytica Chimica Acta 282 (3): 603-612. https://doi.org/10.1016/0003-2670(93)80125-5. [DOI]
  • 📚 textbook Anonymous. 1989. "Some Applications of Uv and Vis Spectrophotometry." Studies in Analytical Chemistry: 260-303. https://doi.org/10.1016/b978-0-444-98882-9.50012-8. [DOI]
  • 📚 textbook Anonymous. 1989. "Basis of Spectrophotometry in the Uv and Vis Regions." Studies in Analytical Chemistry: 13-46. https://doi.org/10.1016/b978-0-444-98882-9.50005-0. [DOI]

REST: /wp-json/molgod/v1/spectra/uv-vis/109-99-9?solvent=water&path_length_cm=1

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📚 REFERENCES (Aggregate bibliography, Chicago Author-Date) 108 items

All scientific sources cited in the accordions above for CAS 109-99-9. Format: Chicago Manual of Style 17th ed., Author-Date system.

🗄️ Scientific databases

  1. NIST. 2026. NIST Chemistry WebBook: CAS 109-99-9. Gaithersburg, MD: National Institute of Standards and Technology. https://webbook.nist.gov/cgi/cbook.cgi?ID=109-99-9. (Accessed 2026-11-12.)
  2. AIST. 2026. Spectral Database for Organic Compounds (SDBS): CAS 109-99-9. Tsukuba, Japan: National Institute of Advanced Industrial Science and Technology. https://sdbs.db.aist.go.jp/. (Accessed 2026-11-12.)
  3. PubChem. 2026. PubChem Compound Summary: CAS 109-99-9. Bethesda, MD: National Center for Biotechnology Information (NCBI), National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/#query=109-99-9. (Accessed 2026-11-12.)
  4. ECHA. 2026. C&L Inventory and REACH Registration: CAS 109-99-9. Helsinki: European Chemicals Agency. https://echa.europa.eu/information-on-chemicals/annex-vi-to-clp. (Accessed 2026-11-12.)

📐 Standards / Guidelines

  1. ICH. 2026. "ICH Harmonised Guideline: CAS 109-99-9." Geneva: International Council for Harmonisation. https://database.ich.org/sites/default/files/Q1A%28R2%29%20Guideline.pdf. (Accessed 2026-11-12.)
  2. National Fire Protection Association (NFPA). 2024. "NFPA 30: Flammable and Combustible Liquids Code." NFPA, Quincy, MA. https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=30.
  3. Occupational Safety and Health Administration (OSHA). 2023. "29 CFR 1910.106 — Flammable Liquids." U.S. Department of Labor, Federal Register. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.106.
  4. European Chemicals Agency (ECHA). 2024. "Annex VI to Regulation (EC) No 1272/2008 (CLP) — Harmonised Classification and Labelling." ECHA, Helsinki / Official Journal of the European Union. https://echa.europa.eu/regulations/clp/clp-classification.
  5. European Committee for Standardization (CEN). 2016. "EN 374-1:2016 — Protective gloves against dangerous chemicals and micro-organisms — Part 1: Terminology and performance requirements for chemical risks." CEN, Brussels. https://standards.cencenelec.eu/dyn/www/f?p=205:110:::::FSP_PROJECT,FSP_ORG_ID:38536,6080&cs=1B0DAA8B85DF42E4A2C70E5D71F0BFA32.
  6. European Committee for Standardization (CEN). 2001. "EN 166:2001 — Personal eye-protection — Specifications." CEN, Brussels. https://standards.cencenelec.eu/dyn/www/f?p=CEN:110:0::::FSP_PROJECT:6541&cs=1F1A4E0A78C4DB6A28DBE2E8C29D89DCF.
  7. European Committee for Standardization (CEN). 2009. "EN 14605:2005+A1:2009 — Protective clothing against liquid chemicals — Performance requirements for clothing with liquid-tight (Type 3) or spray-tight (Type 4) connections." CEN, Brussels. https://standards.cencenelec.eu/dyn/www/f?p=CEN:110:0::::FSP_PROJECT:21581&cs=1A04A2D3C7CC58E9E6CB58D55F7EBFB7E.
  8. National Institute for Occupational Safety and Health (NIOSH). 2017. "Recommendations for Chemical Protective Clothing: A Companion to the NIOSH Pocket Guide." U.S. Department of Health & Human Services / CDC. https://www.cdc.gov/niosh/ncpc/default.html.
  9. Occupational Safety and Health Administration (OSHA). 2011. "Personal Protective Equipment — General requirements." U.S. Department of Labor — 29 CFR 1910.132. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.132.

📖 Books

  1. Hansen, Charles M. 2007. Hansen Solubility Parameters: A User's Handbook, 2nd ed.. Boca Raton, FL: CRC Press. https://www.routledge.com/Hansen-Solubility-Parameters-A-Users-Handbook/Hansen/p/book/9780849372483.
  2. Barton, Allan F. M. 1991. CRC Handbook of Solubility Parameters and Other Cohesion Parameters: 2nd ed.. Boca Raton, FL: CRC Press. https://www.routledge.com/CRC-Handbook-of-Solubility-Parameters-and-Other-Cohesion-Parameters/Barton/p/book/9780849301766.
  3. Connors, Kenneth A., Gordon L. Amidon, and Valentino J. Stella. 1986. Chemical Stability of Pharmaceuticals: A Handbook for Pharmacists, 2nd ed.. New York: Wiley. https://doi.org/10.1002/0471734683.
  4. Rumble, John R., ed. 2019. CRC Handbook of Chemistry and Physics: 100th Edition. Boca Raton, FL: CRC Press. https://hbcp.chemnetbase.com/.
  5. Urben, Peter G. 2017. Bretherick's Handbook of Reactive Chemical Hazards, 8th Edition. Academic Press / Elsevier, Oxford. https://www.sciencedirect.com/book/9780081010594.

📘 Monographs

  1. IARC. 2026. IARC Monographs on the Identification of Carcinogenic Hazards to Humans: CAS 109-99-9. Lyon, France: International Agency for Research on Cancer, World Health Organization. https://monographs.iarc.who.int/list-of-classifications/. (Accessed 2026-11-12.)

📄 Scientific articles (peer-reviewed)

  1. Stefanis, Emmanuel, and Costas Panayiotou. 2008. "Prediction of Hansen Solubility Parameters with a New Group-Contribution Method." International Journal of Thermophysics 29: 568-585. https://doi.org/10.1007/s10765-008-0415-z.
  2. Stoll, Vincent S., and John S. Blanchard. 1990. "Buffers: Principles and Practice: In Methods in Enzymology, vol. 182." San Diego: Academic Press. https://doi.org/10.1016/0076-6879(90)82008-P.

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