工作场所空气中磷酸测定方法的研究

建立了用抗坏血酸为还原剂的分光光度法测定工作场所空气中磷酸的方法。微孔滤膜采集空气中的磷酸雾,水洗脱后,在酸性溶液中,与钼酸铵生成磷钼杂多酸,以抗坏血酸还原,生成磷钼蓝,在700nm波长下用分光光度计测定。方法曲线的相关系数r=0.9999,线性范围0～200μg,检出限0.068μg/mL,相对标准偏差为0.17%～0.96%,加标回收率为94.0%～103.9%。用本方法测定工作场所空气中磷酸,效果很好、线性关系良好、检出限低、准确度及精密度高。

Determination of phosphoric acid in workplace air

The Spectrophotometry which used ascorbic acid as deoxygenated agent was stud- ied for the determination of phosphoric acid in the atmosphere of workplace. Methods： In this method, the mist of phosphoric acid was first sampled by microporous membrane and then eluted with water. In the acid solution, it would be reacted with ammonium molybdate to generate ammonium phosphomolybdate which was deoxygenized by ascorbic acid to molybdenum blues, using the 700nm wavelength UV-visible spectrophotometer determined. Results：The correlation coef- ficient of the obtained curve was 0. 9999, liner range was 0--200ug, the detection limit was 0. 068 ug/mL, the relative standard deviation was 0.17%-0.96%, and the recovery rate was between 94.0% and 103.9%. Condusion. The results showed the method have good linearity, low detection limit, high accuracy and precision for the determinination of phosphoric acid in the atmosphere of workplace.