Mercury content of whole cigarettes, cigars and chewing tobacco packets using pyrolysis atomic absorption spectrometry with gold amalgamation

A commercially available mercury (Hg) analyzer (AMA-254), based on sample pyrolysis, gold amalgamation, and atomic absorption spectrometry (AAS), was evaluated and optimized for the direct determination of total-Hg in three common tobacco products: cigarettes (n = 30; five lights, five regulars for three brands), cigars (n = 4; one brand) and chewing tobacco packets (n = 5; one brand). Advantages of the method are ease of use (automated analysis without sample preparation), rapid analysis (<10 min per sample), and a low detection limit (0.04 ng of Hg). The accuracy was determined by analysis of certified reference materials (Virginia Tobacco Leaves and Tomato Leaves) and samples fortified with NIST SRM 1573a. Precision for the analyses was <12% relative standard deviation (RSD) for each sample type. Mercury content and concentration (fresh weight basis) was highest in the cigar (54.7 ± 6.0 ng/cigar; 20.8 ± 1.0 ng g−1), followed by cigarettes (11.7 ± 1.2 ng/cigarette; 13.0 ± 1.3 ng g−1) and chewing tobacco (4.4 ± 0.5 ng/packet; 6.3 ± 0.6 ng g−1); moisture content was 6.2%, 12.1% and 54.8%, respectively. The cigaretteʹs tobacco and filler accounted for >97% of the Hg found in the whole cigarette. Differences in mean concentrations of Hg between the individual brands of cigarettes and between the “light” and “regular” designations were not significant, and chewing tobacco did not differ significantly from most cigarette brands; however, cigars had significantly higher concentrations than both cigarettes and chewing tobacco. There were also no differences for the Hg content of saliva obtained before and during use of chewing tobacco. This study demonstrates that analyzers based on pyrolysis–amalgamation–AAS are suitable for monitoring total-Hg levels in these tobacco products, but the data should not be interpreted for real human exposure from inhaled smoke or absorbed via saliva.