工作场所空气中磷酸标准测定方法的改进

Improved Standard Method for Determining Phosphoric Acid in The Air of Workplace

目的对目前工作场所空气中磷酸的标准测定方法进行改进,使之可以在实际工作中应用。方法改变溶液的酸度及还原剂的配制方法,找出最佳分析条件。结果磷酸含量在2.5～70μg之间呈良好线性关系,回归方程为Y=0.0095X+0.0058,r=0.9998,检出限为1.5μg/5 ml。当采集的空气样品体积为75 L时,最低检出浓度为0.1 mg/m3。回收率为98.4%～106.0%,RSD为2.0%～4.5%。结论改进后的方法可用于实际工作。

[ Objective ] To improve the standard method for determining phosphoric acid in the air of workplace, so as to make it to be applied in practical work. [ Methods] The acidity of the solution and preparation method of reduetant were changed, and the optimum analysis conditions were discovered. [ Results] Good linear relationship showed as phosphate content of 2.5 - 70 μg. The regression formula was Y = 0. 0174 X ＋ 0. 0187, r = 0. 999, the detection limit was 1.5 μg,/5 ml. when the volume of collected air samples were 75L, the minimum detection concentration was 0. 1 mg/m^3. Recovery was 98. 4% - 106. 0%, RSD was 2.0% - 4.5%. [ Conclusion] The improved method can be applied in practical work.