[Determination of 8 N-nitrosamines in the workplace air by GC-MS/MS method]

Objective: To establish a method for the determination of eight N-nitrosamines (N-nitrosodimethylamine, N-nitrosodimethylamine, N-nitrosomethylmethylamine, N-nitrosodibutylamine, N-nitrosopropylamine, N-nitrosomorpholine, N-nitrosodianiline and N-nitrosopiperidine) in the air of workplace by gas chromatography-tandem mass spectrometry (GC-MS/MS) . Methods: From January to August 2023, eight N-nitrosamines in the air of workplace were collected by ThermoSorb/N column, eluted with 4 ml methanol-dichloromethane (1∶1 volume ratio), separated by VF-624 ms capillary column, detected by multiple reaction monitoring mode and quantified by external standard method. The detection limit and precision of the method were also analyzed. Results: The linear range of the method for the determination of eight N-nitrosamines was 1.0-20.0 μg/L, the correlation coefficient was 0.9993-0.9999, the detection limit was 0.051-0.132 μg/L, and the minimum quantitative concentration was 0.030-0.078 μg/m(3) (calculated by collecting 22.5 L of air sample and eluting with 4.0 ml stripping liquid). The within-run precisions were 2.05%-6.89% and the between-run precisions were 2.41%-8.26%. The desorption rates were 67.20%-102.60%. The sample can be kept at least 7 days at 4 ℃. Conclusion: GC-MS/MS method for the determination of eight N-nitrosamines in workplace air has high sensitivity and good precision, and can accurately determine the content of eight N-nitrosamines in workplace air.