Wu Qinghui

Determination of Amino Acids in Tobacco Flavors by Liquid Chromatography Tandem Mass Spectrometry

A method for determining 18 amino acids in tobacco flavors by liquid chromatography tandem mass spectrometry(LC-MS/MS) was developed. Using L-norvaline(Nva) as an internal standard, the sample was extracted by 10% methanol-water solution(HCl concentration of 0.1 mol/L), and the extract was directly analyzed by LC-MS/MS after filtering with a 0.22 μm aqueous phase filtration membrane. The results showed that: the linear correlation coefficients of 18 amino acids were above 0.9990 in the range of 0.1-10 μmol/L, and the recoveries of 3 standard addition levels ranged from 85.4% to 110.0% with the relative standard deviation(RSD) of 1.3%-4.9%. The limits of detection(LODs) and the limits of quantification(LOQs) of the method were 0.00005-0.1 μmol/L(S/N=3) and 0.0002-0.3 μmol/L(S/N=10), respectively. This method is accurate, sensitive and suitable for determining the amino acids in tobacco flavors.

Relationships Between Design Parameters of Material and Deliveries of 7 Harmful Components and Hazard Index of Mainstream Cigarette Smoke

In order to investigate cigarette materials on the deliveries of 7 harmful components(CO,HCN,NNK,NH3,B[a]P,phenol and crotonaldehyde) and hazard index of mainstream cigarette smoke,the influencing factors(including the content and type of combustion improver in cigarette paper,the content of flax in cigarette paper,the grammage and air permeability of cigarette paper,the air permeability of tipping paper and plug wrapper,and the pressure drop of filter) were tested individually.The prediction models for harmful components were established with mathematical statistics method basing on 5 design parameters(the grammage of cigarette paper,the air permeability of cigarette paper,plug wrapper and tipping paper and the pressure drop of filter),and the external validation of the models were separately conducted.The results showed that: 1) The said design parameters affected the harmful components and hazard index of mainstream smoke to different extents.Most of the harmful components decreased with the increase of the content of combustion improver in cigarette paper,the grammage and air permeability of cigarette paper,the ventilation rate and pressure drop of filter,while increased with the increase of flax content in cigarette paper and the ratio of Na/K in combustion improver.2) For the 7 harmful components in 10 validation samples,the relative deviations between the forecasted value and detected value were less than 15%,which indicated that the forecasting ability of the models was well.3) HCN,NNK,NH 3,B[a]P,phenol and crotonaldehyde could be selectively reduced by increasing the grammage of cigarette paper and the pressure drop of filter or decreasing the air permeability of tipping paper.