大气中SO2顺序注射光度测定方法的初步研究

基于SO2在微碱性条件下使孔雀绿褪色的反应原理, 结合顺序注射进样技术建立了光度分析测定大气中SO2的方法. 对试剂加入顺序、各种试剂的浓度、注入体积、反应系统流速等实验参数进行了优化. 采用顺序注射进样, 极大地节省了试剂和试样的用量, 显著地提高了分析速度, 可达到60样·h-1. 方法的线性响应范围0.25～4.0 μg·mL-1, 检出限为0.15 μg·mL-1, 11次重复测定的相对标准偏差为1.5%. 对实际样品的回收率为94%～108%.

Determination of Sulfur Dioxide in Air by Sequential Injection Spectrophotometry

A sequential injection spectophotometric method for the determination of sulfur dioxide by decolorizing malachite green in an alkali medium is studied; the decreasing in color is proportional to the amount of sulfur dioxide. The loading sequence, the concentration of reagents, the amount of sample and the flow of reagent rate are optimized by univariate method. With sequential injection sample introducing, the volumes of sample and reagent are reduced greatly and the speed of determination is increased apparently, a throughput of 60 samples/h can be achieved. A liner calibration curve was obtained in range of 0.5-4.0 microg x mL(-1). The determination limit is 0.15 microg x mL(-1), the RSD and the recovery are 1.5% and 94%-108% respectively.