GC-MS/MS Determination of N-Nitrosodimethylamine in Smokeless Tobacco

A method of GC-MS/MS for the determination of N-nitrosodimethylamine in smokeless tobacco was proposed. The sample of smokeless tobacco (0.500 g) was extracted ultrasonically with 10 mL of dichloromethane and the supernatant was purified with Si solid phase extraction column. The DB-WAX quartz capillary chromatographic column was used for GC separation and the multiple reaction monitoring mode was adopted in MS determination.Internal standard method was used for quantitative. Linearity range of N-nitrosodimethylamine was found between 0.2 μg·L^-1 and 10 μg·L^-1 with detection limit (3s) of 0.018 ng·g^-1 and lower limit of determination (10s) of 0.060 ng·g^-1. Tests for recovery were made by standard addition method at the concentration levels of 3, 6, 10 ng, giving values of recovery and RSD's (n=5) in the ranges of 94.7%-101% and 2.8%-6.8% respectively.