Simultaneous determination of nine N-nitrosamine species in water by gas chromatograph-mass spectrometer in electron ionization(EI)mode

For the EI mode,there were low responses for N-nitrosamines. Large volume of water samples and concentration factor up to 5000 were adopted and detection conditions of GC/MS in the EI mode were explored for the analysis of nine N-nitrosamine species at ng/L level in water. The N-nitrosamines in water were extracted by coconut charcoal. The calibration curves obtained for nine N-nitrosamine species were in the range of 2-1000滋g/L(r 2 =0.9976-0.9996). The limit of detection(LOD)for nine N-nitrosamine species spiked at 10ng/L ranged from 0.8ng/L to 4.3ng/L by the SD method and ranged from 0.2ng/L to 5.0ng/L by the S/N method. The recoveries of nine N-nitrosamine species spiked at 10ng/L,50ng/L and 200ng/L were 75%-103%,62%-101% and 48%-97%,respectively. The recoveries meet the general requirements 70%-130% of the EPA Method 521,except for NDPhA spiked at 50 ng/L(62%)and 200 ng/L(48%). The precision of the method measured by relative standard deviation (RSD) was less than 12% for all N - nitrosamines spiked at 10 ng/L,50 ng/L and 200 ng/L levels. The GC-EI/MS method for the