大气细粒子阳离子表面有机活性物质分析方法的优化

分别从样品前处理和分析测定两方面对大气细粒子中阳离子表面有机活性物质的二硫蓝分光光度分析法进行优化，并采用优化方案对北京市大气细粒子进行了分析.结果表明:① 优化的最佳样品前处理条件中超声提取频率为40 Hz、初始水浴温度为30℃、超声提取时间为30 min；② 优化的最佳分析测定条件中二硫蓝使用量为1.29 mg（0.5 mL的2.58 g/L二硫蓝溶液）、最佳静置时间为30 min、醋酸盐缓冲液（pH为5）最佳使用量为3 mL.二硫蓝分光光度法优化方案标准曲线的R2为0.9986，线性较好.采用该优化方案测得的北京市大气细粒子中阳离子表面有机活性物质浓度的平均值为12.87 pmol/m3，其浓度水平数量级是阴离子表面有机活性物质的1/10，其浓度水平高于英国诺威奇与爱丁堡，但低于马来西亚吉隆坡. 

Optimization Study on Analytical Methods for Cationic Surface Organic Active Substances in Atmospheric Fine Particles

The optimization of the analytical conditions of Disulfine Blue Spectrophotometry for the characterization of surface organic active substances in fine particles was carried out from two aspects of the pretreatment and the analytical parameters, respectively.In addition, the optimized method was applied to measurement of the mass concentrations of the surface organic active substances in fine particle samples collected in Beijing.The results showed that:(1) The optimal frequency, initial bath temperature and extraction time for ultrasonic extraction were 40 Hz, 30℃ and 30 min, respectively.(2) The optimal amount of chromogenic reagent was 1.29 mg of disulfine blue (0.5 mL 2.58 g/L of disulfine blue solution); the optimal standing time was controlled in the range of 30 min.; and the optimal amount of the auxiliary reagents were 3 mL of acetate buffer(pH=5).The determined average value for the concentration of the cationic surface organic active substances in fine particles was 12.87 pmol/m3, acquired by using the optimal experimental schemes for the Disulfine Blue Spectrophotometry, which was 1/10 of the anionic surface organic active substances.The concentration level of Beijing was higher than the concentrations levels of Norwich and Edinburgh in the United Kingdom, but was lower than the concentrations levels of Kuala Lumpur in Malaysia.