OnGuard II Ag柱对磷酸盐含量测定的影响

目的研究前处理过程中使用OnGuard Ⅱ Ag柱对磷酸盐测定值的影响。方法以食品安全国家标准方法为基础,设计了2部分的实验内容:测定不同浓度磷酸钠溶液中磷酸盐的含量;测定经过前处理后的2种鱼肉和3种肉松样品中磷酸盐的含量。结果在2部分实验的前处理中使用OnGuard Ⅱ Ag柱后,磷酸钠溶液实验中随着磷酸钠溶液浓度的增加,磷酸盐溶液的测定值回收率由106%降至15.0%;样品实验中过柱后鱼肉和肉松的磷酸盐测定值降至未过柱的8.67%~10.3%。结论在无基质和有基质干扰的情况下,使用离子色谱测定磷酸盐含量过程中使用OnGuard Ⅱ Ag柱,均会严重影响到磷酸盐测定的准确性,尤其会使高浓度磷酸盐样品中磷酸盐的测定值大幅度降低。

Influence of OnGuard II Ag cartridge on the determination of phosphate content

Objective To investigate the effect of OnGuard Ⅱ Ag cartridge on phosphate determination during pretreatment. Methods Based on the national food safety standard method, two parts of the experiment were designed: the determination of the phosphate content in different concentrations of sodium phosphate solutions, the determination of the phosphate content in the two kinds of fish meat and three kinds of meat floss samples after pretreatment. Results After using the OnGuard Ⅱ Ag cartridge in the pretreatment of two experiments, the recovery rates of the measured value of the phosphate solution decreased from 106% to 15.0% as the concentration of the sodium phosphate solution increased in the sodium phosphate solution experiment, and the measured value of phosphate of fish meat and meat floss also decreased to 8.67%-10.3% of that before passing through cartridge in food sample experiment. Conclusion In the absence of matrix and matrix interference, the use of OnGuard Ⅱ Ag cartridge in the determination of phosphate content by ion chromatography will seriously affect the accuracy of phosphate determination, especially in high-concentration phosphate samples, it can lead to a significant decrease in the determination value of phosphate.