Contamination of Chinese salted fish with volatile N-nitrosamines as determined by QuEChERS and gas chromatography-tandem mass spectrometry.

The QuEChERS sample preparation method and gas chromatography-tandem mass spectrometry were employed to determine nine volatile N-nitrosamines (VNAs) in Chinese salted fish. This method was validated by considering calibration plot linearity, selectivity, matrix effects, trueness, precision, limits of quantification and specificity. Fifty-four samples of Chinese salted fish obtained from five provinces were analyzed. The results indicated that the concentrations of one VNA, N-nitrosodimethylamine in 57.4% of the samples exceeded the acceptable limit (the China national standard value of 4μgkg-1), and total VNA contents in 68.5% of the samples exceeded the acceptable United States Department of Agriculture limit of 10μgkg-1 for cured meats. In addition, total VNAs in marine salted fish that exceeded the acceptable limit were statistically higher than those in freshwater salted fish. The present study suggests that VNA contamination in Chinese salted fish continues to be serious, and deserves stricter management by the authorities.