食品科学 ›› 2001, Vol. 22 ›› Issue (1): 70-71.

• 分析检测 • 上一篇    下一篇

快速测定磷酸(氢)钙中磷含量

胡冬生   

  1. 南海出入境检验检疫局
  • 出版日期:2001-01-15 发布日期:2012-02-14

Rapid Determination of Phosphorus in Ca3(PO4)2 or CaHPO4

 HU  Dong-Sheng   

  • Online:2001-01-15 Published:2012-02-14

摘要: 通过加入硝酸镧作沉淀释放剂,使H2PO4-中的H+游离出来。用标准氢氧化钠溶液直接滴定游离出来的H+(pH调节和滴定过程都由自动电位滴定仪来完成),根据所消耗的氢氧化钠溶液体积,求出样品中磷的含量。本方法操作简单、快速、重现性好,省略硅钼柠酮沉淀标准方法中许多繁琐的步骤,而测定结果与标准方法测定结果无显著性差异。本方法适合于pH=4.2时水溶性的磷酸盐中磷含量的测定。采用本方法测定磷酸(氢)钙中磷含量,结果令人满意。

关键词: 磷酸(氢)钙, 硝酸镧, pH=4.2, 自动电位滴定仪

Abstract: H+ was freed from H2PO-4 by adding La(NO3)3 solution as precipitation releasing agent.The concentration of the freed H+ was directly titrated by the standard NaOH solution.The content of phosphorus of Ca3(PO4)2 or CaHPO4 was calculated by the consumption of the standard NaOH solution.All the operations of titration and pH adjustment were completed by the Automatic Potentiometric Titrator.These operations in this method were simple and rapid with good precision .The complex processes in the standard method such as precipitation and filtration and scrubbing,were omitted in this method,but the results of the method were the same as those of the standard method.This method may be used to tast water soluble phosphate at pH=4.2.

Key words: Ca3(PO4)2 CaHPO4 La(NO3)3 pH=4.2 The Automatic Potentiometric Titrator