普通过磷酸钙磷肥中全磷的快速测定

A Quick Determination on Measuring the Holophosphate Content in Ordinary Superphosphate Phosphate Fertilizer

研究了电位滴定法快速测定普通过磷酸钙磷肥中全磷含量的方法。用浓硝酸溶解试样,硝酸钡和阳离子交换树脂除去干扰离子,同时加入六次甲基四胺—硝酸缓冲溶液控制溶液的酸度(pH=5.4)。在乙醇体系中,采用硝酸铅标准溶液进行电位滴定,二阶微分法确定硝酸铅标准溶液的滴定终点体积。方法的RSD为0.68%～0.72%,回收率为99.96%～100.0%。

The author in this paper studies a quick analytical method, namely potentiometric titration on measuring the holophosphate content in ordinary superphosphate phosphate fertilizer. Dissolving the measured sample with concentrated nitric acid ,the interference ion is eliminated through the ion-exchange resin and barium nitrate with hexamine -nitric acid adding to control the reagent acidity(PH=5.4).The potentiometric titration is implemented with lead nitrate standard solution. The end point of titration is determined with the second order differentiation. RSD of the method is 0.68%-0.72% and the recovery is 99.96%-100.04%.