连续流动注射间接测定空气中的五氧化二磷

建立连续流动注射间接测定空气中五氧化二磷的方法。空气中的五氧化二磷用过氯乙烯滤膜或滤筒采样,加入去离子水反应生成正磷酸,过滤、洗涤、定容后运用连续流动注射仪进行测定。优化了抗坏血酸浓度、硫酸浓度、钼酸盐浓度以及恒温室温度等影响显色的因素。最佳条件下,实际样品五氧化二磷加标回收率为96.0%~102%,相对标准偏差在4%以下;采样体积为300 L时,方法检出限为0.001 6 mg/m~3。t检验结果表明,所建方法与现行国标法的测定结果无显著性差异。方法分析速度快、重现性好、灵敏度高,适用于空气中五氧化二磷的测定。

Indirect Determination of Phosphorus Pentoxide in Air by Flow Injection Analysis

A method was established for indirect determination of phosphorus pentoxide in air by flow injection analysis. The phosphorus pentoxide in air was collected by perchlorethylene filter membrane or cartridge, and then reacted with water to produce orthophosphate. The orthophosphate was analyzed by flow injection analysis after filtering, washing and constanting volume. The effects of ascorbic acid concentration, sulfuric acid concentration, molybdate concentration and thermostat temperature on the chromogenic reaction were optimized. Under the optimal conditions, the recovery rate of spiked samples was 96.0%-102% with RSD below 4%. The method detection limit was 0.001 6 mg/m³ when the sampling volume was 300 L. According to the t test, the present method showed no significant difference compared with national standard method. The present method had advantages of convenience, wide linear range, good reproducibility and high sensitivity, which was suitable for determination of phosphorus pentoxide in air.