Detection and Determination of Methanol and Further Potential Toxins in Human Saliva Collected from Cigarette Smokers: A 1H NMR Investigation

Introduction/Objectives: The deleterious health effects of tobacco smoking are now widely recognized and documented. High-resolution 1 H NMR analysis of human saliva provides a high level of valuable molecular information regarding the nature and levels of a wide range of both endogenous and exogenous agents therein. This investigation focused on the detection of molecular modifications to the salivary 1H NMR profiles of cigarette smokers following smoking of a single cigarette product. Methods: Cigarette-smoking human participants (6 female, 7 male) provided saliva samples both prior and subsequent to smoking a single cigarette (the former following a 12 hr. overnight fasting/smoking-abstention period). A group of n = 7 non-smoking controls also provided saliva samples before and after a 4.0 min. ‘smoking mimic’ time period.1 H NMR analysis of supernatants derived therefrom was conducted at an operating frequency of 400 MHz. Results: 1H NMR analysis revealed that single cigarette smoking episodes gave rise to substantial increases in the salivary concentrations of methanol (p<10-6) and propane-1,2-diol (p = 2.0 x 10-4), i.e. ca. 40- and 3.2-fold escalations in their mean levels respectively; the identity of methanol was confirmed by GC-MS analysis. As expected, there were no modifications to these tobacco smoking marker levels in control group participants following a corresponding 4.0 min. non-smoking period. Conclusions: 1H NMR analysis of human saliva provided much valuable information on the infiltration of toxins and further agents from cigarette smoke into this biofluid. The marked elevations in salivary methanol levels observed are of much concern in view of its documented toxicological properties and adverse health effects.