SIMULTANEOUS DETERMINATION OF N,N-DIMETHYLFORMAMIDE, N-MONOMETHYLFORMAMIDE AND N-HYDROXYMETHYL-N-METHYLFORMAMIDE IN RAT PLASMA BY CAPILLARYGAS-CHROMATOGRAPHY

A capillary gas chromatographic method with nitrogen-phosphorus detect ion for the simultaneous quantitative determination of N,N-dimethylfor mamide, and its two metabolites, N-monomethylformamide and N-hydroxyme thyl-N-methylformamide, in rat plasma ma has been developed. The metho d involves a single extraction step with ethyl acetate-acetone (4:1, v /v). The extract is injected into a fused-silica capillary column coat ed with Carbowax 20M. A temperature gradient (65-1 10-degrees-C) is ap plied, and the three products can be separated within 10 min. The quan titation limits, using 25 mul of rat plasma, for N,N-dimethylformanide , N-monomethylformamide and N-hydroxymethyl-N-methylformamide are 0.4, 0.4 and 2 mug/ml, respectively. This method is suitable for toxicokin etic studies in rats.