GC-MS determination of N-Nitrosodimethylamine in Waste Water Containing 1,1-Dimethyl-hydrazine

Hyphenation of gas chromatography and mass spectrometry was applied to the determination of N-nitrosodimethylamine (NDMA),a probable degradation compound of 1,1-dimethyl hydrazine,in 1,1-dimethylhydrazine containing waste water,using selected ion monitoring mode. The waste water sample was pretreated by steam distillation,extraction with dichloromethane and concentration by blowing with nitrogen. Linear relationship between the peak area and concentration of NDMA was obtained in the range of 0.31-1.54 mg·L-1,corresponding to the linear regression equation Y=2.60×104 x-4.49×103 (r=0.999 5),with detection limit (S/N=3) of 2 μg·L-1. Tests for recovery and precision of this method were made by adding 2.016 μg and 10.08 μg of NDMA to 100 mL of distilled water (i.e. blank solution),and determined by the proposed method,the results of recovery obtained were 88.8% and 89.3%,results of RSD′s found were 4.82% and 4.96% respectively.