新鲜过磷酸钙磷肥中有效磷的快速测定

Quick Determination of the Effective Phosphorus in the New Calcium Superphosphate

研究了用电位滴定法快速测定新鲜过磷酸钙磷肥中有效磷含量的方法 .首先用一定浓度H2 SO4 萃取有效磷后 ,通过阳离子交换树脂和硝酸钡除去干扰离子 ,用六次甲基四胺硝酸缓冲溶液控制试液的酸度 (pH =5 .4 ) ,在乙醇体系中用一定浓度的硝酸铅标准溶液进行电位滴定 。

In this paper, quick determination of the content of the effective phosphorus in the new calcium superphosphate by means of potentiometric titration has been researched. First, H2SO4 of some density is dissolved to extract the sample. Second, through the ion exchange and the adding barium nitrate the jamming ion is got rid of. Third, the reagent acidity is controlled by hexamethylenetetramine-HNO3 (pH=5.4). Next, the potentiometric titration is done with lead nitrate of some density as standard solution. Finally, the end point of titration is determined by the method of second order.