Simultaneous determination of nine nitrosamines in fermented vegetables by GC-MS/MS

Tóm tắt

In this study, nine nitrosamines were identified in fermented vegetables by gas chromatography tandem mass spectrometry (GC–MS/MS), using NDMA-d6 as the internal standard and a DB–17MS capillary column (30 m × 0.25 mm × 0.25 µm). The QuEChERS sample preparation procedure was optimized to achieve improved extraction efficiency for the analytes. The extracted sample was injected in splitless mode with a volume of 2 µL, with helium as a carrier gas at 1 mL/min, an EI ionization source at 280℃, and a collision energy of 50 eV. The method was validated according to EC 2021/808, showing good selectivity; a calibration curve was generated over the range of 0.5–20 ng/mL with correlation coefficient R² ≥ 0.995; recoveries ranged from 83.0 to 119.6%; relative standard deviation (RSD) and relative standard deviation for repeatability (RSDr) ranged from 4.62–11.06% and 7.65–11.9%, respectively, meeting the acceptance criteria. The limits of detection and quantification were 0.15 µg/kg and 0.5 µg/kg, respectively. The method was applied to analyze 108 fermented vegetable samples from the market, of which 14 samples were found to contain nitrosamines. The nitrosamines detected were mainly NDMA, NDEA, and NDBA, consistent with published results related to nitrosamine contamination in fermented foods.