[Study on the method of using ICP-MS to determine microelements in the animal feed].

The method for the determination of microelements such as Cu,Zn,Fe,Mn,Cr,Cd,Pb,As and Se in the animal feed by inductively coupled plasma-mass spectrometry was developed.The operation parameters,spectrum interference,matrix effect and memorial effect were studied in detail.Under optimal condition,the detection limits of these nine elements were from 2.03×10-3 to 3.17 μg·L-1,and the linear range was over three orders with a correlation coefficient above 0.999.This method was applied directly to determine microelements in real samples involving the standard wheat powder,formular feed and pre-mix feed.The determination results of microelements in the standard wheat powder accorded with reference results.The recovery of microelements in the formular feed was from 86% to 115%,and the relative standard deviations ≤8.2%(n=6).The results of elements content in the pre-mix feed were identical with those determined by national standard method.This method is simple,sensitive, accurate and can perform simultaneous multi-elements determination compared with conventional method of animal feed determination.The results were satisfactory.