离子色谱法检测乳制品中的微量碘

Determination of Micro Amounts of Iodide Ion in Dairy Products by Ion Chromatography

建立用离子色谱/电导检测法测定乳制品中的微量碘的分析方法。试样经乙酸沉淀蛋白,NaOH洗去脂肪,超声波、涡旋振摇提取,离心分离后,依次过Dionex OnGuard II RP小柱、0.22μm微孔滤膜处理后进样检测,选用IonPac AS19阴离子交换分离柱,在线产生40mmol/L~70mmol/L KOH淋洗液梯度洗脱,流速1.0mL/min,以抑制型电导检测器检测。结果表明:碘I-在0.0μg/L~200μg/L质量浓度范围内具有良好的线性关系,相关系数为0.9998;方法检出限为0.055mg/kg;在0.12、0.24、1.20mg/kg三个添加浓度水平下,平均回收率为91.42%~97.88%。该方法线性范围广,专属性强,准确性和精密度良好,操作较简便,可用于乳制品中碘离子的含量检测。

A new method was established to determine micro amounts of iodide ion in dairy products by ion chromatography with conducting detection.Acetic acid was applied for protein precipitation of samples.The fat was washed away from samples with sodium hydroxide.Ultrasonic wave method and vortex vibration method was applied for extraction.The samples were separated by centrifugation,then filtrated with Dionex OnGuard II RP column and 0.22μm membrane.The samples of solution were injected and analyzed.IonPac AS19 was selected as the separation column.The gradient 40mmol/L~70mmol/L KOH solution with a flow rate 1.0mL/min was used as eluents.Autogenerated conducting detection ASRS ULTRA II 4mm was used.The results showed that the linear relation of perchlorate was good in the range of 0.0μg/L~200μg/L(r=0.9998).The detection limit was 0.055mg/kg.At the concentration addition levels of 0.12,0.24 and 1.20mg/kg,the average recovery rates were 91.42%~97.88%.The method had a wide linear range,strong exclusivity,good repeatability and accuracy,which is suitable for the quantitative detection of iodide ion in dairy products.