Determination of Urinary Heterocyclic Aromatic Amines in Smokers and Non-Smokers by Using Sensitive and High Throughput Liquid Chromatography-Tandem Mass Spectrometry

Abstract

Tobacco smoking is the single leading cause of preventable death in the United States. A number of heterocyclic aromatic amines (HCAA) are harmful and potentially harmful constituents of tobacco smoke. In the present study, a sensitive, precise and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with high sample throughput was developed to quantitate HCAA in urine from both smokers and nonsmokers. We find that the concentrations of 2-amino-9H-pyrido[2,3-b] indole (AC) and 2-amino-3-methyl-9H-pyrido[2,3-b] indole (MeAC) in smokers were significantly higher than those in non-smokers (P<0.05). No significant differences were found in urinary level of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) between smokers and non-smokers (P>0.05). Two beta-carboline HCAA, harman and norharman, were present at similar concentrations in both smokers and non-smokers (P>0.05). The urinary levels of AC and MeAC were also found to be highly correlated with tobacco-specific carcinogen exposure as assessed by urinary 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol, NNAL) (r2 >0.7). Except for AC, MeAC, PhIP, harman, and norharman, other HCAA in the urine samples of both smokers and non-smokers were too low to be detected. In conclusion, a sensitive and high throughput analytical method has been established to monitor urinary HCAA in smokers and non-smokers. AC and MeAC are the most prevalent HCAA resulting from tobacco smoke exposure.