Determination of N-nitrosodimethylamine in environmental aqueous samples by isotope-dilution GC/MS-SIM

An analytical method for the determination of N-nitrosodimethylamine (N-NDM A) in environmental aqueous samples has been developed using isotope diluti on gas chromatography/mass spectrometry in the selected ion monitoring mode (GUMS-SIM). After deuterated N-nitrosodimethylamine (d(6)-N-NDMA) as surro gate standard was added to the samples, the analytes were extracted with me thylene chloride, dried with anhydrous sodium sulfate, and concentrated in a rotary evaporator. The concentrated extracts were analyzed by GC/MS-SIM a fter adding N-nitrosodiethylamine as an internal standard. The method detec tion limit for N-NDMA was 0.003 pg/muL and was validated by an analysis of a fortified water sample. The method was applied to real samples.