臭氧与异戊二烯液相反应实验探究

Experimental Study on the Liquid Phase Reaction of Ozone and Isoprene

本论文利用紫外可见分光光度计、液相色谱质谱联用仪器测量了异戊二烯与臭氧的液相化学反应产物,探究了反应时间、异戊二烯浓度、pH值、重金属离子等因素对反应产物的影响规律.实验结果表明,异戊二烯与臭氧反应的主要产物是甲基丙烯醛,次要产物是甲基乙烯酮.甲基丙烯醛的产生浓度随着反应时间的延长而逐渐增大,随异戊二烯浓度的增加呈现先增加后减小的规律.当异戊二烯的浓度大于5.0 mmol/L时,产生甲基乙烯酮产物,该产物浓度随着异戊二烯浓度的增加而逐渐增大.酸性条件有利于甲基丙烯醛和甲基乙烯酮的产生.除镍离子外,重金属离子存在时则能显著促进甲基丙烯醛和甲基乙烯酮的形成.这为研究生物源污染物液相反应形成二次有机气溶胶机理提供了实验依据。

In this paper,the UV visible spectrophotometer,liquid chromatography mass spectrometry instrument were used to measure the liquid phase products of the chemical reaction of isoprene and ozone.The effects of formaldehyde concentration,reaction time,isoprene concentration,metal ions and other factors on the reaction products were investigated in this study.The experimental results show that the main products of isoprene and ozone are methylacrolein and the secondary product is methyl vinyl ketone.The concentration of methyl acrolein gradually increased with the increase of reaction time,and increased with the increase of isoprene concentration.When the concentration of isoprene is greater than 5.0 mmol/L,producing methyl vinyl ketone products,the concentration of the product increases with the increase of isoprene concentration.Acidic conditions are beneficial to the production of methyl acrolein and methyl vinyl ketone.In addition to nickel ion,the presence of heavy metal ions can significantly promote the formation of methyl acrolein and methyl vinyl ketone.This provides an experimental basis for the study of the secondary organic aerosol mechanism of the liquid phase reaction of biological pollutants.