| Our country is a tobacco superpower. Environmental tobacco smoke (ETS) caused by smoking is one of the main reasons for indoor environment pollution. At present, the number of people in our country exposed to secondhand smoke is already more than5.4millions. Protecting non-smokers from the dangers of secondhand smoke has attracted national attention. Since the framework convention on tobacco control became effective in our country in January2006, a lot of work has been done. In recent years, People crowded secondhand smoke exposure condition have improved in our country, but it still has a great distance to make smokeless in all indoor workplaces and indoor public places, one important reason is that the air sampling and the detection method of EST is insufficiency. ETS is a complex ingredient. And nicotine is a specificity content in the ETS, so it is often been used to analyse ETS’s pollution situation. It is very important to establish a good efficient sampling method and high sensitivity test method to determine the level of nicotine in indoor environment, but in our country, the aspect of work still is not perfect.This study used passive sampler to gain air sampling. And the former processing conditions were optimized. Glass fiber diaphragm was dipped with1%of acid hydrogen sodium. Methylene chloride as extraction solvent and sodium hydroxide as eluent, their volume was2mL and4mL respectively. Ultrasonic extraction time was20minutes. Whirlpool mixed time was2minutes. Extraction efficiency can reached98%reproducibly.A capillary column GC-NPD method was established for the determination of nicotine in the indoor environment air. The influence of the column temperature, the flow rate and other factors on chromatographic conditions was studied. The optimal conditions including a DB-5capillary column with temperature programming was used. Using the splitless injection mode, and the injection volume was1μL. Nitrogen was used as the carrier gas, and its flow rate was1.8mL/min. The flow rate of hydrogen, air, and tail gas blowing was3mL/min,65mL/min and10mL/min respectively. The injection temperature was250℃, and the detector temperature was300℃. Under the optimal conditions, the working curve was linear in0.05～5μg/mL. The linear correlation coefficient is0.9996. The detection limit and quantitation limit in the air was0.01μg/m3and0.04μg/m3respectively. The relative standard deviations were3.5%～4.4%. This method was used for the determination of nicotine in real samples, and the result was satisfactory.Additionally, this study also established the indirect fluorescence spectrometry method to measure the content of nicotine in ambient air. The following were the best test conditions. The slit width was2.5nm. Scanning voltage was600V. Scanning speed was600nm/min. Fluorescein sodium was chosed as fluorescence reagent, and its concentration was9×10-6mol/L in10mL color tube. The most suitable pH value was6, and the reaction time was10minutes. The constant water-bath temperature was35℃. In the best conditions, The linear correlation coefficient of working curve was0.9992, and the linear range was from0.1to7μg/mL, and its relative standard deviation was4.3%～5.5%. The detection limit was1μg/m3in the air. Similarly, the actual samples were admeasured though this method. The recoveries were87.0%～105%.Two methods could be used for the determination of nicotine in indoor environment air. The GC-NPD method was better selective, higher sensitivity and accuracy than indirect fluorescence method, but the later was easier operation. |
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