Determination of Copper, Manganese, Zinc and Nickel in Herbal Ephedrae by ICP-MS with Microwave Digestion

The contents of traceelements of copper, manganese, zinc and nickel in Chinese traditional medicineHerbal Ephedrae were determined by inductively coupled plasma mass spectrometry(ICP-MS) with microwave digestion. The ion source and the mass spectrometeroperation parameters were optimized. The metal concentrations in HerbalEphedrae are 2.7，33.2，1.1 and 4.23 mg/kg for Cu, Mn, Zn and Ni,respectively. During the measurement, ⁷²Ge was used as the internalstandard element. The detection limits (S/N=3) of the method are 0.09—0.37 μg/L.The results show that the linearities of the four elements are 0—100 μg/L，and the correlation coefficient are 0.999 6—0.999 9. The relative standard derivations (RSDs) are1.26%—6.01%. The averagerecoveries in a sample at three levels are in the range of 87.1%—113.3%. The results of determining the four elementsin the certified reference materials of GBW10028 are all within the ranges ofstandard values.