Abstract: A method based on liquid chromatography tandem mass spectrometry was developed for the simultaneous determination of four tobacco-specific N-nitrosamines(TSNAs) in gum-based tobacco products.Using NNN-d₄,NNK-d₄,NAB-d₄,NAT-d₄ as internal standards,samples were successively extracted with 0.05 mol/L HCl aqueous solution,cleaned up by HLB solid phase extraction cartridge,separated by an Agilent Poroshell 120 SB-C₁₈ column,and analyzed by a tandem mass detector under multi-reaction monitoring(MRM) scan mode.The results showed that:1) the limits of quantification of TSNAs varied from 0.026 to 0.076 ng/mL,the recoveries ranged from 80.00% to 126.86% and relative standard deviation(RSD) from 2.99% to 8.32%;2) the total concentration of TSNAs ranged from 5.13 to 13.76 ng/g.The concentrations of NNN and NAT were much higher and their sum accounted for 91.23% to 95.71% of total TSNAs yields.The method is fit for the simultaneous analysis of TSNAs in gum-based tobacco products.