氯乙酸副产气中总硫含量间接分光光度法测定

Indirect spectrophotometric determination of total sulfur content in byproduct gas of chloroacetic acid production

研究了铬酸钡分光光度法应用于氯乙酸副产混合气中总硫含量测定的实例。探讨了气体采集、样品溶液处理和铬酸钡悬浮液配制等关键问题。硫元素经碱液吸收和双氧水氧化完全转化为硫酸根,硫酸根再与铬酸钡悬浊液反应,定量置换出铬酸根,溶液的吸光度即与硫酸根的浓度成正比。该方法的测定波长为372 nm,硫酸根质量浓度在0～10 mg/L线性关系好。该方法操作简单,精密度和准确度均符合测定要求,适用于工厂气体的实时监测。

Application of barium chromate spectrophotometry in determination of total sulfur content in by-product gas mixture of ehloroaeetie acid production was studied. Critical problems, such as gas collection, sample solution treatment, and barium chromate suspension preparation were discussed. Sulfur in various compounds in gas mixture was totally converted to sulfate radical by oxidizing with H2 02 after absorption by alkaline agent. Obtained sulfate radical would react with barium chromate suspension,proportionally displacing chromate. Solution absorbance was thus proportional to the concentration of sulfate radical. The absorbance was found to be at 372 nm by this method. The method had a good lineafity at 0 - 10 mg/L sulfate radical. Precision and accuracy of the easy operating method meet the test requirements in practical applieation.