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.
Related solvents
Other selectivity group V to compare with Dichloromethane.