分光光度法测定底质总磷的方法探讨

在一定条件下，用硫酸和过氧化氢进行消解，使不溶性磷酸盐和有机磷转化为正磷酸盐，待测液与钼酸盐反应生成磷钼杂多酸，加入还原剂抗坏血酸后转变成蓝色络合物，进行比色测定。实验表明，该方法回收率为93．4％～99．7％，检出限为0．009mg／L，RSD为4．0％。方法简便、可靠，能满足环境监测底质总磷分析的需要。

A Research of Detecting Total Phosphate in Substrate by Spectrophotometry

Under certain conditions, the digestion with sulfuric acid and peroxide turns the insoluble phosphate and organic phosphorus into orthophosphate. When the test solution and molybdate react into phosphomolybdic hetero- poly acid, which turns into the blue complex if added with the reduce agent Ascorbic acid, the colorimetric deter- mination is then conducted. The experiment shows that the recovery of this method is 93.4% -99. 7% , the detec- tion limit is 0. 009mg/L and the RSD is 4. 0%. It is an easy and reliable way to meet the need of TP analysis in environmental monitoring substrate.