[Determination of elements of hypericum perforatum L. in Xinjiang by microwave digestion-ICP-AES].

Sample digestion by microwave is of some merits: simple, rapid, saving agents, nonpollution and being easy digested. HNO3-HClO4 (5:1) was used as a microwave digestion agent. A direct method is reported for the determination of Fe, Ca, Mg, Zn, Mn, Cu, Na, K, Ba, Al, Pb and Cr in Hypericum perforatum L. in Xinjiang by inductively coupled plasma atomic emission spectrometry(ICP-AES). The selection of digestion conditions of the technique is described. The recoveries for these elements were 93.2%-103.0%, and the relative standard deviation (RSD) of the twelve samples were 0.4%-2.9%. According to standard sample GBW07602 bush twigs and leaves, the authors checked the method for accuracy and precision. The results were found to be basically consistent with the reference values. It was proved that the method features satisfactory precision and accuracy. The method was applied to the determination of plant materials with good agreement.