基于电感耦合等离子体-串联质谱技术测定乳制品中26种无机元素

Determination of 26 Inorganic Elements in Dairy Products by Inductively Coupled Plasma-Tandem Mass Spectrometry

建立电感耦合等离子体-串联质谱测定乳制品中26种无机元素的分析方法。在串联质谱条件下,选择无气模式、碰撞气(He)模式及反应气(H_(2)、O_(2)、NH_(3)/He)模式,分别对26种元素进行测定并筛选出最优测定模式。结果表明:每种元素在选用合适的测定模式下能够获得线性良好的标准曲线,相关系数均大于0.9990;26种无机元素的检出限范围为0.00003361~0.04371 mg/kg,加标回收率在95.50%~104.21%之间,11次重复分析的相对标准偏差3.94%;6种乳制品中含量较高的元素为Na、Mg、K、Ca、P、Fe、Zn,而重金属元素Cr、As、Cd、Pb的含量较低,均低于国家标准的限量要求。该方法样品前处理简单、灵敏度高、检出限低,测定结果准确,可用于乳制品中无机元素的检测。

An inductively coupled plasma-tandem mass spectrometry(ICP-MS/MS)method was established for the analysis of 26 inorganic elements in dairy products.Under MS/MS conditions,the 26 elements were detected in the no gas,collision gas(He)or reaction gas(H_(2),O_(2),NH_(3)/He)mode and the optimal mode was selected for each of the elements.The results showed that calibration curve with good linearity was obtained for each element in the appropriate detection mode with a correlation coefficient greater than 0.9990.The detection limits of the 26 inorganic elements ranged from 0.00003361 to 0.04371 mg/kg.The spiked recoveries were between 95.50%and 104.21%,with a relative standard deviation(RSD)≤3.94%(n=11).The contents of Na,Mg,K,Ca,P,Fe and Zn were higher and the contents of the heavy metal elements Cr,As,Cd and Pb were lower in six kinds of dairy products,all of which were lower than the national standard limits.The method was characterized by simple pretreatment,high sensitivity,low limit of detection and high accuracy and could be used for the detection of inorganic elements in dairy products.