Research On The Effect Of Cigarette Smoke PH On The Release Of Key Components Of Mainstream Smoke

The objective of this thesis was to explore the influence of pH in the cigarette mainstream smoke on the release of major chemicals.The analysis method for pH and free base nicotine in cigarette smoke,the influence of pH in cigarette mainstream smoke on the release of major chemicals were reviewed.The analysis methods of pH based on the papers and broad and free base nicotine in cigarette smoke were developed.The effect of pH on free nicotine,seven special ingredients and the acidic,neutral and alkaline aroma components were summarized.Five main aspects were included in the thesis.(1)The method that was used to determine pH of the cigarette mainstream smoke has been optimized,and it was researched that extraction solvent is isopropanol-neutral water(v/v=1:1),extraction volume is 25 mL,extraction time is 30 min.The sample repeatability and reproducibility were done using this method.Standard deviation of the day in 0.17%and 0.33%respectively,estimate of between-day standard deviation is 0.25%.(2)The method that was used to determine free nicotine of cigarette mainstream smoke has been optimized,and it was researched that the nicotine was affected by extraction agent,the volume of extraction agent is 50 mL,the extraction time is 30min.The nicotine and free nicotine was well separated by the extraction systems CHCl3-neutral water(pH=7.00±0.02).The determination result is repeatability and reproducibility relative standard deviation of free nicotine below 5%and the recovery rate of free nicotine about was 85%.The determination result of 25 cigarette samples show:for increasing the Physical satisfaction that is lack for the nicotine content decreasing,it had been become a trend of domestic and foreign that free nicotine was controlled by increasing the proportion of free nicotine.(3)The adding amount of citric acid was significantly positive(negative)correlation with the pH in the mian stream smoke.In a certain range,the change of the pH in the mainstream smoke has no significant effect on the nicotine.Overall,with the increase of pH in cigarette smoke,the free nicotine and rate of free nicotine was rising.(4)In the research scope,increasing the pH of cigarette smoke,the deliveries of phenol,HCN,B[?]P,NNK,CO decreased,while that of crotonaldehyde had no obvious change;the deliveries of NH3 was increased and then decreased with the increasing of cigarette smoke pH;The change of puff number induced by the pH of cigarette smoke was one of the reasons causing the change of deliveries of the seven special components.The deliveries of CO and NH3 is low when the puff number is relatively low,however,it has upward trend when the high level of puff number.(5)In the research scope,the release rate of 3,5-dimethyl pyridine,2-ethyl pyridine,3-methyl indole have a positive correlation with the pH in cigarette smoke.Increasing the pH,the deliveries of 3,5-dimethyl pyridine,2-ethyl pyridine,3-methyl indole increasd;There was no obvious change between neutral aroma components and pH;The release rate of 4-methyl phenol acid aroma components,2,6-dimethyl pheno 2-Methoxy-4-vinylphenol,vitamin A acetate have a negative correlation with the pH in cigarette smoke,increasing the pH of cigarette smoke,the deliveries decreased.