离子色谱法检测三聚磷酸盐中不同形态磷酸盐的研究

研究了离子色谱法测定食品添加剂三聚磷酸盐中不同形态磷酸盐含量的方法。用NaOH 溶液梯度淋洗，选用1.0ml/min 的流速，成功测定了三聚磷酸盐中各组分(正磷酸盐、焦磷酸盐、三聚磷酸盐和三偏磷酸盐)的含量。各磷酸盐在测定条件下有很好的线性范围，检测限(S/N=3)为0.010～0.063mg/L，保留时间的相对标准偏差为0.38%～0.79%，峰面积的相对标准偏差为2.21%～6.96%，样品的加标回收率为97.45%～106.89%，整个分析过程可在10min 内完成。实验结果表明，该方法具有分析时间短、灵敏度高、线性范围宽、试剂用量少等优点。

Ion Chromatography for Content Determination of Various Phosphate Forms in Tripolyphosphate

An ion chromatography method was developed for determination of contents of various phosphate forms in tripolyphosphate, in the present study. Phosphates were eluted with100 mmol/L NaOH solution in gradient at a flow rate of 1.0 ml/ min. The method presented good linearities between the peak areas and concentrations of orthophosphate, pyrophosphate, tripolyphosphate, and trimetaphosphate and their detection limit ranged from 0.010 to 0.063 mg/L. The relative standard deviations (RSD) of the retention time varied between 0.38% and 0.79% and the RSD of the peak area was between 2.21% and 6.96%. The recoveries of the above phosphates in spiked tripolyphosphate sample ranged from 97.45% to106.89%. This complete analysis procedure lasted 10 min. Our results indicated that this method is rapid and accurate with a wide linear range and less consumption of chemicals.