Extraction from Moist Snuff with Artificial Saliva of Benzo[a]pyrene and Other Polycyclic Aromatic Hydrocarbons

The present study evaluated in vitro extractability of various polycyclic aromatic hydrocarbons (PAHs) from moist snuff, when the extracting agent was water or artificial saliva. The extraction was performed on nine brands of moist snuff samples that are commercially available and were purchased from the market in January 2018. The moist snuff brands were selected to represent brands with different tobacco cut size descriptors and flavors. For the measurement of PAHs, two different analytical methods were used, an HPLC (High Performance Liquid Chromatography) method for measuring only benzo[a]pyrene (BaP) and a GC/MS/MS (Gas Chromatography Tandem Mass Spectrometry) method for measuring 21 PAHs (including BaP). These methods were modifications of preexistent methods reported in the literature. The results for BaP indicated that by extracting 500 mg of freeze-dried moist snuff with 6 portions of 20 mL water (120 mL), or with 4 portions of 20 mL artificial saliva, followed by two portions of 20 mL water, the BaP remains close to 100% in the solid material and it is not detected in the extracting solution. PAHs with a molecular weight similar or heavier than BaP also showed no extractability. Lighter PAHs such as fluorene, phenanthrene, anthracene, and 5-methylanthracene showed a relatively good extractability. An intermediate group including fluoranthene, pyrene, and benz[a]anthracene showed some extractability in the conditions of this in vitro experiment. This study is not a substitute for clinical studies regarding PAH uptake in human users of moist snuff. However, the results indicate very limited bioavailability of BaP and heavier PAHs from moist snuff. Higher, but variable bioavailability was indicated for lighter PAHs. Important implications of these findings are that: 1) measurably different BaP content of two moist snuff products is unlikely to result in any meaningfully different consumer exposure to BaP; and 2) biomarkers for one PAH cannot necessarily be used as a reliable indicator of exposure to another PAH, particularly if the molecular weights of the precursor PAHs differ since their bioavailabilities can be very different. [Beitr. Tabakforsch. Int. 28 (2019) 214–223]