Determination of primary aromatic amines in smokeless tobacco products
The list of harmful and potentially harmful constituents (HPHCs) published by the FDA in 2012 features six primary aromatic amine (PAA) compounds: 1-aminonaphthalene (1-ANP), 2-aminonaphthalene (2-ANP), 4-aminobiphenyl (4-ABP), o-anisidine (o-AND), 2,6-dimethylaniline (DMA), and o-toluidine (o-TOL). Of these six PAAs, 2-ANP, 4-ABP, and o-TOL have been deemed to be Group 1 carcinogens by the International Association for Research on Cancer (IARC). PAAs in mainstream smoke are thought to be combustion products formed from the tobacco’s nitrogen-containing constituents. Smokeless tobacco products (STPs) would, therefore, be expected to be relatively free from PAAs, but some tobacco curing processes may introduce PAA contaminants through exposure to smoke and heat. In this study, we sought to determine if PAAs are present in a range of STPs and if there is any correlation to the tobacco types used in the product. Using a procedure adapted from a draft CORESTA method for the analysis of PAAs in mainstream cigarette smoke by GC-MS, we screened a variety of reference and market products for their PAA content. For many products, the levels were below either the verified quantitation or detection limits for each analyte. However, elevated and quantifiable levels of the Group 1 carcinogens, o-TOL and 2-ANP, were observed in products containing significant proportions of dark-fired tobacco. The CORESTA research product CRP3.1, for instance, is a dry snuff product for which the tobacco blend is 62 % dark-fired tobacco, and was found to contain approximately 4.9 ng/g o-TOL and 0.17 ng/g 2-ANP. Elevated levels of the Group 2B carcinogens DMA and o-AND were also found (0.48 and 0.57 ng/g, respectively). For comparison, a Kentucky 3R4F cigarette smoked under ISO conditions generates an average of 45 ng/cig o-TOL, 5.8 ng/cig 2-ANP, 3.2 ng/cig DMA, and 2.5 ng/cig o-AND. Results from our market product survey will be presented and discussed.