Determination of trace elements in commonly consumed medicinal herbs by ICP-MS and multivariate analysis

The concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Rb, Sr and Pb elements in thirty medicinal herb samples widely consumed in Kayseri, Turkey were determined by using inductively coupled plasma mass spectrometry (ICP-MS). The samples were digested with concentrated nitric acid and hydrogen peroxide in a microwave system. The decreasing sequence of the mean metal levels in medicinal herbs is as follows: Fe > Sr > Mn > Zn > Rb > Cu > Ni > Cr > Co > Pb. Correlation analysis, principal component analysis and cluster analysis were applied to the data matrix to evaluate analytical results. It was found that four principal components account for 80.6% of the total variance in the data. In order to verify the accuracy of the method, GBW07605 Tea Certified Reference Material was analysed.