二苯碳酰二肼分光光度法测定工作场所空气中的二氧化硫

Determination of Sulfur Dioxide in Air of Workplace by Diphenylcarbazide Spectrophotometry

建立一种用分光光度法间接测定工作场所空气中二氧化硫的新方法。用（1＋1000）高氯酸溶液吸收空气中的二氧化硫,使其氧化成硫酸根,加铬酸钡悬浊液反应生成硫酸钡沉淀,释放出铬酸根,在酸性条件下用二苯碳酰二肼显色测定铬,由此间接测定二氧化硫的含量。方法曲线的相关系数为r=0.9985,检出限为0.10μg.mL-1,线性范围为0~5μg.L-1,相对标准偏差为2.87%～4.52%,加标回收率为96%～107%。本方法操作简单、准确、重复性好、灵敏度高,结果满意。

A new method for the indirect determination of sulfur dioxide in air of workplace by spectrophotometry was proposed.The sulfur dioxide in the air of workplace was absorbed by（1＋1000） perchloric acid solution and oxidized to sulfate radical.After adding barium chromate suspension,the barium sulfate precipitate was produced and the chromate was released.Using spectrophotometry at 550nm to determine chromium,the trace sulfur dioxide in air was obtained indirectly.The correlation coefficient of the curves obtained by the methods was 0.9985,the detection limit was 0.10μg/mL,linear range was 0～5μg/mL,the relative standard daviation was 2.87%～4.52%,and the average recovery of samples was between 96%～107%.The method used for determination of sulfur dioxide in air of workplace was simple-operation,fast and accurate.