Analysis of Nicotine and Non-nicotine Tobacco Constituents in Aqueous Smoke/Aerosol Extracts by UHPLC and Ultraperformance Convergence Chromatography-Tandem Mass Spectrometry.

The non-nicotine constituents of tobacco may alter the reinforcing effects of nicotine, but the quantitative and qualitative profiles of these chemicals in tobacco products such as electronic cigarettes (e-cigarettes), cigars, and waterpipe tobacco are not well characterized. The objective of this work was to develop and validate analytical methods to utilize saline both as an extraction solvent for smoke condensates from cigarettes, little cigars, and waterpipe tobacco and aerosols from e-cigarettes and as a delivery vehicle of nicotine and non-nicotine constitents for nonclinical pharmacological studies. Ultrahigh-performance liquid chromatography was used to analyze nicotine and acetaldehyde, and a novel ultraperformance convergence chromatography-tandem mass spectrometry method was developed to analyze anabasine, anatabine, cotinine, myosmine, nornicotine, harmane, and norharmane. Linearity was confirmed for each standard curve with correlation coefficients (r) ≥ 0.99, and relative errors (RE) for the standards were ≤±10% over the calibration ranges. Method validation was performed by preparing triplicate samples in saline to mimic the composition and concentration of each analyte in the smoke or aerosol condensate and were used to determine method accuracy and precision. Relative standard deviation values were ≤15% and mean RE ≤15% for each analyte at each concentration level. Selectivity of the methods was demonstrated by the absence of peaks in blank vehicle or diluent samples. Storage stability was assessed over ∼45 days. Precision (%RSD ≤ 13) and recovery (percent of day 0 ≥ 80%) indicated that the saline formulations of all four products could be considered stable for up to ∼45 days at 4-8 °C. Therefore, the use of saline both as an extraction solvent and as a delivery vehicle adds versatility and improved performance in the study of the pharmacological effects of constituents from mainstream smoke and aerosols generated from cigarettes, little cigars, waterpipes, and e-cigarettes.