[Study on determination of rare earth La and Ce in feed by using ICP-MS].
An advanced method for the determination of rare earth La and Ce in animal feed by using of inductively coupled plasma mass spectrometry was studied. The operation parameters for ICP-MS was optimized, the effect of pre-mix feed matrix and formular feed matrix for La and Ce was studied by the conventional method and stepwise dilution method, and the suppression of signal intensity of La and Ce by nitric acid was examined. Under the optimum condition, the limit of determination for La and Ce were 2.62 x 10(-2) microg x kg(-1) and 6.47 x 10(-3) microg x kg(-1), respectively, the linear coefficient was 1.000 0, the dynamical linear range was of 3 order of magnitudes, and the internal standards were In(115) and Tb(159). The developed method was applied to the determination of rare earth La and Ce in pre-mix feed and formular feed, with the recovery > or = 77.8% and the relative standard deviation(RSD) < or = 8.5%, and the testing results were satisfactory.
Wang
Pei-Long
PL
Institute of Quality Standards and Testing Technology for Agricultural Products, China Agricultural Academy of Science, Beijing 100081, China. wplcon99@163.com
Su
Xiao-Ou
XO
D000821:Animal Feed / Q000032:analysis*; D002563:Cerium / Q000032:analysis*; D007811:Lanthanum / Q000032:analysis*; D013058:Mass Spectrometry / Q000379:methods*
D002563:Cerium; D007811:Lanthanum