Solvent · low polarity
Dichloromethane CH2Cl2
Also: DCM, methylene chloride
Common medium-polarity strong solvent for normal-phase (silica) HPLC and preparative/flash column chromatography; frequent component of mobile phases with hexane/heptane and modifiers. Widely used as a low-boiling extraction and sample-prep solvent, and as a GC solvent/diluent. Its low UV transparency (cutoff ~233-235 nm) limits use in low-UV detection; not used in reversed-phase (immiscible with water).
Compiled by Hemant RawatLast reviewed July 2026How we verify
Properties
- Formula
- CH2Cl2
- CAS number
- 75-09-2
- UV cutoff
- 233 nm
- Snyder polarity index (P′)
- 3.1
- Selectivity group
- V
- Eluotropic strength ε° (silica)
- 0.3
- Boiling point
- 39.8 °C
- Viscosity (25 °C)
- 0.44 cP
- Refractive index (nD²⁰)
- 1.4242
- Density
- 1.325 g/mL
- Water miscibility
- immiscible
- USP <467> class
- Class 2
Safety
- suspected human carcinogen (IARC Group 2A / NTP reasonably anticipated)
- acutely toxic - CNS depressant
- metabolized in vivo to carbon monoxide (carboxyhemoglobin risk)
- volatile / high vapor pressure (~350 mmHg at 20 C)
- combustible vapors at elevated temperature (practically non-flammable in air at ambient conditions but can form flammable mixtures)
- irritant to skin/eyes/respiratory tract
- possible reproductive/developmental concern
- NIOSH potential occupational carcinogen; IDLH 2300 ppm
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 Dichloromethane mixes with
Miscible with: 1-Propanol, 1,2-Dichloroethane, 1,4-Dioxane, 2-Propanol, Acetic acid, Acetone, Acetonitrile, Benzene, Carbon tetrachloride, Chloroform, Cyclohexane, Diethyl ether, Dimethyl sulfoxide, Ethanol, Ethyl acetate, Iso-octane, Methanol, Methyl ethyl ketone, Methyl isobutyl ketone, MTBE, n-Butanol, n-Butyl acetate, n-Heptane, n-Hexane, N-Methylpyrrolidone, n-Pentane, N,N-Dimethylacetamide, N,N-Dimethylformamide, Pyridine, tert-Butanol, Tetrahydrofuran, Toluene, Triethylamine.
Immiscible with: Water — these form two layers.
Check any specific pair on the interactive miscibility chart.
Using Dichloromethane in HPLC/GC
Common medium-polarity strong solvent for normal-phase (silica) HPLC and preparative/flash column chromatography; frequent component of mobile phases with hexane/heptane and modifiers. Widely used as a low-boiling extraction and sample-prep solvent, and as a GC solvent/diluent. Its low UV transparency (cutoff ~233-235 nm) limits use in low-UV detection; not used in reversed-phase (immiscible with water).
Its Snyder polarity index is 3.1 (selectivity group V), and its UV cutoff of 233 nm limits low-wavelength 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.