[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.