Abstract A simple and reliable analytical method was established for the quantitative determination of five phosphates (orthophosphate, pyrophosphate, trimetaphosphate, tripolyphosphate, and hexametaphosphate) in dairy products by ion chromatography (IC). The samples were deproteinized with 2% trifluoroacetic acid, defatted with n-hexane, and then purified on a C18 solid phase extraction cartridge. Five phosphates were separated on an IonPacTM AS11-HC analytical column (250 mm × 2 mm) and an IonPacTM AG11-HC guard column (50 mm × 2 mm) with gradient elution of 30-60 mmol/L NaOH, then detected by a suppressor type conductivity detector. The peak areas were linearly valuated with the concentration of the five compounds with good linear coefficients (not less than 0.9986). The limits of detection ranged from 0.1 mg/L to 0.6 mg/L. The average recoveries were within the range of 83.0–117.8% with the RSDs below 9.0%. The concentration of the five phosphates in the treated samples remained relatively stable within 48 h. The proposed procedure has been applied to the determination of the five analytes in several dairy product samples with satisfactory results. Graphical Abstract

中文翻译：

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离子色谱法同时测定乳制品中的五种磷酸盐

摘要 建立了乳制品中五种磷酸盐（正磷酸盐、焦磷酸盐、三偏磷酸盐、三聚磷酸盐和六偏磷酸盐）的离子色谱法（IC），建立了一种简便可靠的分析方法。样品用 2% 三氟乙酸脱蛋白，正己烷脱脂，然后在 C18 固相萃取柱上纯化。五种磷酸盐在 IonPacTM AS11-HC 分析柱 (250 mm × 2 mm) 和 IonPacTM AG11-HC 保护柱 (50 mm × 2 mm) 上分离，梯度洗脱为 30-60 mmol/L NaOH，然后通过抑制型电导检测器。峰面积用线性系数良好（不小于0.9986）的5种化合物的浓度进行线性评估。检测限范围为 0.1 mg/L 至 0.6 mg/L。平均回收率在 83.0-117.8% 的范围内，RSD 低于 9.0%。处理过的样品中五种磷酸盐的浓度在 48 小时内保持相对稳定。建议的程序已应用于测定几种乳制品样品中的五种分析物，结果令人满意。图形概要