Analysis of α- and β-carbolines in mainstream smoke of reference cigarettes by gas chromatography-mass spectrometry

The levels of 2-amino-9H-pyrido[2,3-b]indole (AuC or 2-amino-u-carboline), 2-amino-3-methyl-9H-pyrido[2,3-b]indole (MeAUC or 2amino-3-methyl-(x-carboline), 9H-pyrido[3,4-b]indole (norharman), and 1-methyl-pyrido[3,4-b]indole (harman) have been determined in the mainstream smoke condensate from three reference cigarettes, namely Kentucky reference IR5F, Kentucky reference 2R4F, and CORESTA CM4. The amino-alpha-carbolines, and norharman and harman (beta-carbolines) can be classified as heterocyclic aromatic amines (HAAs) and are listed as biologically active agents in the mainstream smoke of cigarettes. For the analysis, the mainstream smoke condensate from cigarettes was collected on a filter pad, the analytes were isolated using solid-phase extraction (SPE), and quantified without derivatization on a GC-MS. Total amounts of carbolines found in the condensate increased from ultralight IR5F to full-flavor CM4 cigarettes. The level of harman was about 250 ng/cigarette for the IR5F cigarette and about 1025 ng/cigarette for the CM4 cigarette. Norharman was typically three times more abundant than harman. The AuC was found at about 10 times lower level compared to harman, and MeAalphaC was about 50 times lower than harman. The use of reference cigarettes can provide a common measure for laboratories to assess carboline amounts among cigarette brands. (C) 2004 Elsevier B.V. All rights reserved.