工作场所空气中二氧化硫的分光光度测定法

Determination of Sulfur Dioxide in Air of Workplace by Spectrophotometry

目的建立一种分光光度法测定工作场所空气中二氧化硫的新方法。方法用(1+1 000)高氯酸溶液吸收空气中二氧化硫,生成的硫酸根与铬酸钡悬浊液形成硫酸钡沉淀和铬酸根,铬酸根与二苯碳酰二肼生成紫红色络合物,在540 nm处测定吸光度值,计算出二氧化硫含量。结果方法的校准曲线相关系数r=0.999 6,线性范围0.10～2.0μg/ml,检出限0.04μg,最低检出浓度0.10μg/ml,相对标准偏差为1.11%～5.23%,加标回收率为92.3%～101.3%。结论用该方法测定工作场所空气中的二氧化硫,选择性强,干扰少,灵敏准确,结果可靠。

[Objective]To establish a new method for determination of sulfur dioxide in the air of workplace. [Methods]The sulfur dioxide in air of workplace was absorbed and oxidized to sulfate radical by（1＋1 000） perchloric acid solution.After adding Barium chromate suspension,it become barium sulfate and chromate which connected with diphenylcarbazide into purplish red compound,and absorbance value was measured at wavelength 540 nm,then sulfur dioxide content was calculated. [Results]The correlation coefficient of calibration curve r=0.999 6,the linear range was 0.10~2.0 μg/ml.Detection limit was 0.04 μg,minimum detectable concentration was0.10 μg /ml.The RSD was1.11%~5.23% and the recovery rate was 92.3 %~105%. [Conclusion]The method is sensitive,accurate and reliable with good selectivity and less interference in detection of sulfur dioxide in the air of workplace.