离子色谱法测定复配磷酸盐中的正磷酸盐、焦磷酸盐、聚磷酸盐的含量

Determination of Different Forms of Phosphate in Compound Phosphate by Ion Chromatography

确立离子色谱法同时检测复配磷酸盐中正磷酸盐、焦磷酸盐、聚磷酸盐、偏磷酸盐含量的样品处理方法和检测条件。用Ion Pac AS11-HC型色谱柱为分离柱和25~90mmol,l的氢氧化钾淋洗液为流动相,电导检测器进行分析。结果表明正磷酸钠、焦磷酸钠、聚磷酸钠在2~200 mg/L浓度范围内线性良好(其相关系数分别为0.9978、0.9993、0.9994),样品中正磷酸钠、焦磷酸钠、聚磷酸钠-的加标回收率分别为99.4%、98.5%、99.5,检出限分别为0.05、0.05、0.06 mg/kg。

The method of sample preparation and testing conditions were presented for simultaneous detection of orthophosphate, pyrophosphate and polyphosphate contents in compound phosphate by ion chromatography. Determination of the orthophosphate, pyrophosphate and polyphosphate contents in compound phosphate was made with ionPac AS11–HC separation column, 25~90 mmol of KOH as eluent and conductance detection. Very good linear relationships were found for all the three analytes in the range of 2~200 μg/mL. The correlation coefficient of the three analytes were0.9978、0.9993、0.9994. The recoveries rates for orthophosphate, pyrophosphate and polyphosphate in the test samples were 99.4 %, 98.5 % and 99.5 %, and the detection limits were 0.05, 0.05, 0.06 mg/kg respectively.