Solvent · polar aprotic
N,N-Dimethylacetamide C4H9NO
Also: DMAc
Highly polar aprotic solvent used as a mobile-phase component/sample diluent in HPLC and LC-MS for dissolving polymers, poorly soluble APIs, and inorganic salts; strong dissolving power for a wide range of organic and inorganic compounds. High boiling point and high UV cutoff (carbonyl absorbs strongly below ~270 nm) limit its use as a bulk HPLC eluent; more common as a sample solvent. Itself a regulated ICH Q3C/USP <467> Class 2 residual solvent (PDE ~10.9 mg/day).
Compiled by Hemant RawatLast reviewed July 2026How we verify
Properties
- Formula
- C4H9NO
- CAS number
- 127-19-5
- UV cutoff
- 270 nm
- Snyder polarity index (P′)
- 6.5
- Selectivity group
- III
- Eluotropic strength ε° (silica)
- —
- Boiling point
- 165 °C
- Viscosity (25 °C)
- 0.94 cP
- Refractive index (nD²⁰)
- 1.4375
- Density
- 0.937 g/mL
- Water miscibility
- miscible
- USP <467> class
- Class 2
Safety
- combustible liquid (H227, flash point ~63-70 C)
- reprotoxic - GHS Repro. Cat 2 (H361, suspected of damaging fertility/unborn child)
- toxic if inhaled (Acute Tox. Cat 3, H331)
- causes serious eye irritation/damage
- hepatotoxic on chronic exposure
- readily absorbed through skin
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,N-Dimethylacetamide mixes with
Miscible with: 1-Propanol, 1,2-Dichloroethane, 1,4-Dioxane, 2-Propanol, Acetic acid, Acetone, Acetonitrile, Benzene, Carbon tetrachloride, Chloroform, Dichloromethane, Diethyl ether, Dimethyl sulfoxide, Ethanol, Ethyl acetate, Methanol, Methyl ethyl ketone, Methyl isobutyl ketone, MTBE, n-Butanol, n-Butyl acetate, N-Methylpyrrolidone, N,N-Dimethylformamide, Pyridine, tert-Butanol, Tetrahydrofuran, Toluene, Triethylamine, Water.
Partially miscible with: Cyclohexane, Iso-octane, n-Heptane, n-Hexane, n-Pentane — mix only over a limited range.
Check any specific pair on the interactive miscibility chart.
Using N,N-Dimethylacetamide in HPLC/GC
Highly polar aprotic solvent used as a mobile-phase component/sample diluent in HPLC and LC-MS for dissolving polymers, poorly soluble APIs, and inorganic salts; strong dissolving power for a wide range of organic and inorganic compounds. High boiling point and high UV cutoff (carbonyl absorbs strongly below ~270 nm) limit its use as a bulk HPLC eluent; more common as a sample solvent. Itself a regulated ICH Q3C/USP <467> Class 2 residual solvent (PDE ~10.9 mg/day).
Its Snyder polarity index is 6.5 (selectivity group III), and its UV cutoff of 270 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 III to compare with N,N-Dimethylacetamide.