Solvent · nonpolar
n-Pentane C5H12
Also: pentane
Non-polar weak eluent in normal-phase HPLC (start of the eluotropic series, epsilon ~0); UV-transparent (cutoff ~190 nm) making it suitable for low-wavelength UV detection; volatile GC solvent and headspace/extraction solvent; sample dilution and evaporative concentration due to very low boiling point; used similarly to hexane/heptane but more volatile.
Compiled by Hemant RawatLast reviewed July 2026How we verify
Properties
- Formula
- C5H12
- CAS number
- 109-66-0
- UV cutoff
- 190 nm
- Snyder polarity index (P′)
- 0
- Selectivity group
- — (non-selective)
- Eluotropic strength ε° (silica)
- 0
- Boiling point
- 36.07 °C
- Viscosity (25 °C)
- 0.23 cP
- Refractive index (nD²⁰)
- 1.3575
- Density
- 0.6262 g/mL
- Water miscibility
- immiscible
- USP <467> class
- Class 3
Safety
- extremely flammable (flash point ~-49C, low boiling)
- high vapor pressure / explosive vapor-air mixtures
- aspiration hazard (can be fatal if swallowed and enters airways)
- CNS depressant / narcotic at high vapor concentrations
- aquatic/environmental hazard
- static-discharge ignition risk
Reference only. Solvents can be flammable, toxic, or peroxide-forming. Always consult the Safety Data Sheet (SDS) and your lab's protocols before handling.
What n-Pentane mixes with
Miscible with: 1-Propanol, 1,2-Dichloroethane, 1,4-Dioxane, 2-Propanol, Acetic acid, Acetone, Benzene, Carbon tetrachloride, Chloroform, Cyclohexane, Dichloromethane, Diethyl ether, Ethanol, Ethyl acetate, Iso-octane, Methyl ethyl ketone, Methyl isobutyl ketone, MTBE, n-Butanol, n-Butyl acetate, n-Heptane, n-Hexane, Pyridine, tert-Butanol, Tetrahydrofuran, Toluene, Triethylamine.
Partially miscible with: Methanol, N-Methylpyrrolidone, N,N-Dimethylacetamide, N,N-Dimethylformamide — mix only over a limited range.
Immiscible with: Acetonitrile, Dimethyl sulfoxide, Water — these form two layers.
Check any specific pair on the interactive miscibility chart.
Using n-Pentane in HPLC/GC
Non-polar weak eluent in normal-phase HPLC (start of the eluotropic series, epsilon ~0); UV-transparent (cutoff ~190 nm) making it suitable for low-wavelength UV detection; volatile GC solvent and headspace/extraction solvent; sample dilution and evaporative concentration due to very low boiling point; used similarly to hexane/heptane but more volatile.
Its Snyder polarity index is 0, and its UV cutoff of 190 nm is low enough for most UV detection.See what the polarity index means and the full UV cutoff table.
Sources
- University of Toronto (TRACES) — Burdick & Jackson — Solvent UV cutoff table (absorbance = 1 AU, 1 cm cell)
- Stenutz / L. R. Snyder — Solvent polarity index (P′) and selectivity groups
- NIST — Chemistry WebBook — thermophysical properties (BP, density, refractive index)
- PubChem (NIH/NLM) — Compound property records (physical constants, CAS, formula)
- USP <467> / ICH Q3C — Residual Solvents — solvent classification (Class 1/2/3)
Values are compiled from public references and were last verified July 2026. See ourmethodologyfor how we source and verify. Always confirm critical values against primary references and the SDS.