该研究建立了一种基于离子色谱分离/抑制型电导检测的分析方法，用于测定甲壳类水产品中残留的草酸含量。样品经过超纯水超声提取30 min，杂质沉淀后，上清液首先通过聚二乙烯基苯固相萃取柱，然后通过包含银盐形式及H+型的强酸型聚苯乙烯型的阳离子交换树脂柱净化，经IonPac AS11-HC高容量羟基选择性阴离子交换色谱柱分离，氢氧根淋洗液发生器（EG）产生洗脱液进行梯度淋洗，外加水模式在线抑制，电导检测器测定。结果表明草酸在0.05~10.00 mg/L范围内线性相关良好（相关系数为0.9998），方法的检出限为0.033~0.041 mg/kg，定量限为0.11~0.14 mg/kg，回收率为75.71%~88.85%，日内精密度（n=6）为1.74%~3.61%，日间精密度（n=5）小于5%。该分析方法高效灵敏，准确可靠，适用于甲壳类水产品中草酸残留量的检测确证，并为政府监管提供数据支持。

A reliable and sensitive ion chromatography method with solid phase extraction for the determination of oxalic acid in crustacean aquatic products was established. The negative impurities in the extraction solution was precipitated with acetonitrile. The large molecules and Cl- in the supernatant were extracted and purified by the OnGuard Ⅱ RP cartridges and the OnGuard Ⅱ Ag/H cartridges, respectively. The complex matrices sample filtrate was resolved by an IonPac AS11-HC column using hydroxide gradient, which was operated in the online suppression external water mode with suppressed conductivity detection. The results showed that the linear correlation of oxalic acid was good in the range of 0.05~10.00 mg/L (the correlation coefficient was 0.9998). The detection limits (LODs) and the quantitation limits (LOQs) of the method ranged in 0.033~0.041 mg/kg and 0.11~0.14 mg/kg, respectively. The mean recoveries of oxalic acid in crustacean aquatic products ranged from 75.71% to 88.85% with the within-day precisions (n=6) in the range of 1.74%~3.61% and inter-day precisions (n=5) less than 5%. The method was suitable for the quantification of oxalic acid in crustacean aquatic products due to its simplicity and accuracy.

集团科技项目（2019KJ06GZ）