液相色谱-电感耦合等离子体质谱法测定饲料中的六价铬

Determination of hexavalent chromium in feeds by liquid chromatography-mass spectrometry

目的建立液相色谱-电感耦合等离子体质谱法(liquid chromatography-inductively coupled plasma mass spectrometry,LC-ICP-MS)测定饲料中六价铬含量的分析方法。方法以碱性溶液和磷酸缓冲液为提取溶剂,100 mmol/L硝酸铵溶液(pH值7.5)为流动相,采用Dionex IonPac AG19(4 mm×50 mm,4μm)+Dionex IonPac AS19阴离子柱(4 mm×250 mm,4μm)对样品提取液进行分离,电感耦合等离子体质谱进行测定。结果该方法检出限为0.30 mg/kg,线性相关系数大于0.999,精密度RSD<5%,回收率在80%~110%之间。结论该方法科学准确、操作简单快速,可满足各种饲料中六价铬含量的测定。

Objective To establish a method for the determination of hexavalent chromium in feed by liquid chromatography-inductively coupled plasma mass spectrometry.Methods The sample extraction solution was separated by Dionex IonPac AG19(4 mm×50 mm,4μm)+Dionex IonPac AS19 anion column(4 mm×250 mm,4 m)with alkaline solution and phosphate buffer as the extraction solvent and 100 mmol/L ammonium nitrate solution(pH7.5)as the mobile phase.Results The detection limit was 0.30 mg/kg,the linear correlation coefficient was greater than 0.999,the RSD of precision was less than 5%,and the recoveries were in the range of 80%-110%.Conclusion The method is scientific,accurate,simple and fast,it can satisfy the determination of hexavalent chromium in various feeds.