婴幼儿配方乳粉中26种金属元素的测定

测定特殊膳食食品——婴幼儿配方乳粉中金属元素的含量,对比研究电感耦合等离子体质谱(inductively coupled plasma mass spectrometry,ICP-MS)和电感耦合等离子体原子发射光谱(inductively coupled plasma atomic emission spectrometry,ICP-AES)2种测定方法。采用ICP-MS法同时测定婴幼儿配方乳粉中的26种金属元素,以钪(Sc)、铑(Rh)、铋(Bi)3种元素为内标,测定各元素的检出限和定量限,待测元素的相对标准偏差均小于5.0%,回收率为82.80%~110.80%;采用ICP-AES法同时测定婴幼儿配方乳粉中的8种金属元素,各元素的检出限和定量限略高于ICP-MS法,线性关系良好,回收率在91.64%~112.73%之间。2种测定方法都具有较高的精密度和良好的线性关系,ICP-MS法适用的元素种类更多,检出限和定量限更低。

Determination of 26 Metal Elements in Infant Formula

Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) were compared for determining the contents of metal elements in infant formula milk powder. The limits of detection (LOD) and quantitation (LOQ) of ICP-MS were established using Sc, Rh and Bi as internal standards. Relative standard deviations (RSDs) for 26 analytes were less than 5.0%, and recoveries from spiked samples were 82.80%-110.80%. Eight metal elements could be simultaneously determined by ICP-AES, whose LOD and LOQ were slightly higher than those of ICP-MS. Furthermore, ICP-AES exhibited a good linearity and spiked recoveries in the range of 91.64%-112.73%. In the end, we concluded that both ICP-MS and ICP-AES had a high precision and a good linearity, but ICP-MS allowed the determination of a wider range of metal elements with lower LOD and LOQ.