Ion Chromatography In The Analysis Of The Harmful Components Of Cigarette Mainstream Smoke

More and more attention has been paid to the problem of smoking. The WHO Framework Convention on Tobacco Control was subscribed, which means reporting and controlling the harmful components in tobacco and cigarette smoke has been called for a higher demand. At present systematic researches on identification and determination the harmful components in cigarette smoke have not been formed at home. The achievements of foreign research have been mostly consulted by the civil cigarette industries. Systematic researches on analyzing the harmful components and finding the safe character of homemade cigarettes have important meaning on realizing the question of "smoking and health" correctly. Nitrogen oxides and ammonia are part of the primary harmful components in cigarette mainstream smoke. In this dissertation, the methods of determining nitrogen oxides and ammonia in cigarette mainstream smoke were studied, and the forming principle of nitrogen oxides was discussed roughly.(1) A new method for determining nitrogen oxides in cigarette mainstream smoke by ion chromatography (IC) was developed. Absorption bottles equipped with a fritted glass bubbler containing 5% triethanolamine absorbing solution were used to collect nitrogen dioxide in mainstream smoke (Nitrogen monoxide was first oxidized to nitrogen dioxide by chromium trioxide in oxidizing tube). And then NO₂^- and NO₃^- in absorbing solution were determined by IC simultaneously without any pretreatment due to the proper gradient elution procedure. The result showed that the precision was high, and the relative standard deviations were less than 2%. The detection limits were found to be 0.04 mg/L and 0.05mg/L for NO₂^- and NO₃^- respectively. Recoveries of NO₂^-and NO₃^- were found to be ranged between 97% and 101%. This simple, rapid and accurate method was suitable for the determination of nitrogen oxides in cigarette mainstream smoke. The result of this method was compared with the result of Chemiluminescence method, and the data showed that the results of the two methods were accordant. The main cigarette brands in the market were analyzed by the established method. The difference and orderliness of the content of nitrogen oxides in cigarette mainstream smoke of different cigarette brands were discussed.(2) According to the references, the condition of extracting NO₃^- in tobacco and the determining method by IC were established and improved. The sample was ultrasonic vibrated with deionized water, and then was determined by IC with Dionex AS18 anion separation column. The sample was separated well in the selected condition. The results showed that the extracting was completely, the precision of detection was high. In a word, this method was simple, convenient and accurate.The main cigarette brands in the market were analyzed by the established method. And the content relationship between nitrogen oxides and NO₃^- in tobacco was studied. The conclusion showed that they have positive correlation, and the correlation of Virginia cigarettes was a little worse than that of blend cigarettes.(3) Based on the former work, the method for determining ammonia in cigarette mainstream smoke by IC was improved, and the shortage of the reported method was corrected thanks to the proper gradient elution procedure. Also the absorbing condition and chromatographic parameter were optimized. The ammonia in gas phase was absorbed by 50mL of 0.05mol/L H₂SO₄ solution. And the ammonia in Particulate phase was collected by Cambridge filter which was then extracted with the absorbing solution on a shaker. The absorbing solution was determined by IC with Dionex CS12 cation separation column. The sample was separated completely in the selected condition. The results showed that the collection was completely and the method was very steady. And it was simple, convenient, rapid and accurate for the determination of ammonia in cigarette mainstream smoke. The main cigarette brands in the market were analyzed by the established method. The result showed that the content of ammonia in cigarette mainstream smoke was independent of the cigarette's type. And the correlation of content between ammonia and the total Particulate matter in cigarette mainstream smoke was not obvious at all.