WANG Jian-bo,HUANG Xing-hua,WANG Yu-gong,Yuan Xiu-ru

Lanzhou Testing and Quality Supervision Center for Geologicaland Mineral Products,Ministry of Land and Resources,Lanzhou 730050, China

Abstract: A method of nitrate-perchloric acid digestion and inductively coupled plasma-mass spectrometric(ICP-MS) determination of copper,lead,cadmium,cobalt,nickel in tartary buckwheat tea is set up. The method is of high sensitivity,low detection limit, good precision, less matrix interference,accurate,reliable,fast, and simple.Detection limits (3SD,μg/L) for the method are 0.009 for Cu,0.023 for Pb,0.015 for Cd,0.022 for Co and 0.035 for Ni, precisions(RSD，n=12) are 2.5%～3.0% for Cu,2.1%～2.3% for Pb,3.0%～3.8% for Cd,2.5%～2.6% for Co and 1.5%～1.9% for Ni,and recoveries are 95.0%～105.0% for Cu, 95.0%～105.0% for Pb, 98.0%～105.0% for Cd, 95.0%～105.0% for Co and 95.0%～105.0% for Ni respectively, with Rh as the internal standard.The method has been applied to the determination of these elements in the National Standard Reference Materials and the results are in agreement with the certified values. It has been used in the determination of real samples with satisfactory results.

Key words: tartary buckwheat tea; ICP-MS; Cu; Pb; Cd; Co; Ni

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Analysis and Testing Technology and Instruments, Vol. 16, No. 2, 2010, 104-107.