工作场所空气中钼酸铵分光光度法测定磷酸的改进研究

Improvement Research for Determination of Phosphoric Acid in Workplace Air by Ammonium Molybdate Spectrophotometry

为建立可行的钼酸铵分光光度法检测工作场所空气中的磷酸的方法,将样品经震荡处理,酸化、还原反应60 min后(混合酸溶液:15.0 g/L钼酸铵+4.0 mol/L硫酸;还原剂:15.0 g/L硫酸肼)进行分光光度分析,发现目标物的检测在1.74~100μg范围内线性良好(线性相关系数r=0.9998),磷酸最低检出浓度为0.02 mg/m^(3)(以采集75 L空气样品计),不同浓度样品的平均加标回收率在99.4%~102.4%之间。这表明改进后的方法灵敏度高、准确度高,适用实际样品的检测。

In order to establish a feasible ammonium molybdate spectrophotometric method for the detection of phosphoric acid in workplace air,the samples were treated with shaking,and the acidification and reduction reactions were carried out for 60 min(mixed acid solution:15.0 g/L ammonium molybdate+4.0 mol/L sulfuric acid;reducing agent:15.0 g/L hydrazine sulfate)for the spectrophotometric analysis,and the detection of the target was found to be linear in the range of 1.74~100μg(linear correlation coefficient r=0.9998),and the lowest detected concentration of phosphoric acid was 0.02 mg/m^(3)(based on the collection of 75 L of air samples),and the average spiked recoveries of samples with different concentrations ranged from 99.4%to 102.4%.This indicates that the improved method is sensitive,accurate and suitable for the detection of real samples.