Novel method to analysis benzo[ a ]pyrene in filter by liquid chromatography/tandem mass spectrometry: Application to assess mouth level benzo[ a ]pyrene exposure

RATIONALE Benzo[a]pyrene (B[a]P) is a well‐known carcinogenic compound produced from incomplete combustion of organic compounds. During cigarette smoking, cigarette filters trap a portion of mainstream smoke B[a]P and accurate measurement of B[a]P levels in cigarette filter can be used to estimate human exposure level of this compound. METHODS A rapid and sensitive method to quantify B[a]P levels trapped by cigarette filter was developed. The method is based on liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry (LC/APPI‐MS/MS). Validation was provided in smoked cigarette filter. RESULTS The method involved no extensive manual cleanup and concentration steps, hence is easy to use. The limit of detection was 0.064 ng/mL. The recovery ranged from 82.68% to 103.27% and the relative standard deviation (RSD) was less than 7%. A regression model between mainstream cigarette smoke and trapped B[a]P by cigarette filter was established (y = 2.5089x – 0.1851, R 2  = 0.999, n = 6). This model was applied to estimate mouth‐level B[a]P exposure of smokers. CONCLUSIONS The LC/APPI‐MS/MS method developed in this work had an excellent throughput in estimating the mouth‐level exposure under natural human smoking conditions. Mouth‐level B[a]P exposure based on a study of three cigarettes (8, 10 and 13 mg tar levels) showed significant positive correlations with B[a]P trapped by cigarette filter measured (y = 2.5456x – 0.5056, R 2  = 1, n = 249). Copyright © 2014 John Wiley & Sons, Ltd.