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.