Determination of Three Kinds of Amides in Water Paint by Gas Chromatography-Mass Spectrometry

A method of gas chromatography-mass spectrometry was applied to determination of N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylacetamide in water paint. The sample (1.000 0 g) was ultrasonically extracted with 10 mL of dichloromethane at 40℃ for 40 min. After being filtrated with 0.45 μm organic filter, the extracte was separated on a HP-INNOWAX (30 m×0.25 mm, 0.25 μm) capillary chromatographic column, and determined by mass spectrometry under electron impact ion source and selected ion monitoring mode. Linear relationships were found between values of peak area and mass concentration of the three kinds of amides in the same range of 0.5-5.0 mg·L^-1, with detection limits (3S/N) in the range of 1.57-2.38 mg·kg^-1. Test for recovery was made by standard addition method and the values of recovery found were in the range of 81.3%-104%, with RSDs (n=5) less than 3.0%.