Ambient liquid extraction-mass spectrometry for studying release kinetics of flavor components from tipping papers to oral saliva

A quantitative ambient liquid extraction-mass spectrometry method for flavor components on cigarette tipping paper was developed and utilized to quantify their release kinetics from tipping paper into oral saliva during smoking. In this technique, with systematic sampling solvent optimization, minimally invasive sampling (sampling area diameter ≤400 μm) was achieved for <i>in situ</i> quantitation of sweeteners (<i>e.g.</i> stevioside and neotame) and acidulants (citric acid and malic acid) on tipping paper surfaces, with detection limits in the range of 0.22-8.4 μg cm^-2 and quantitation accuracy of 78-118%. The new method enabled rapid <i>in situ</i> identification and quantitation of 14 flavor components in 4 types of commercial tipping papers. Puff-to-puff oral release of flavor components from these tipping papers was simulated, and the new rapid <i>in situ</i> quantitation method was used to study the release kinetic behavior of flavor components from tipping papers. The results show that natural sweeteners such as stevioside and isomaltitol had faster release rates than artificial sweeteners (neotame, acesulfame-K, and sodium saccharin), with 70% release occurring within the first 2-3 puffs and total release quantities per cigarette up to 200 times higher than artificial sweeteners. The absolute concentrations (0.001-0.02 μg mm^-2) and absolute release content (<0.9 μg per cigarette) of artificial sweeteners were significantly below the FAO/WHO recommended daily intake thresholds (equivalent to 660 mg per day for 60 kg body weight), which meets the food safety standards. Moreover, neotame was found to have ideal linear depletion kinetics, maintaining a steady release rate during smoking. The release kinetics of sodium saccharin varied significantly depending on the type of tipping paper. This <i>in situ</i> quantitative release kinetics study offers valuable insights for product design and safety control of flavor tipping papers in the tobacco industry.