Multivariate analyses of major and trace elements in 19 species of herbs consumed in Yunnan, China

Abstract

This study aimed to analyze the concentrations of 10 elements in 19 species of herbs related to medical and edible purpose in Yunnan, China. Microwave-assisted acid digestion was used for all of the dried herbs and element contents were determined by inductively coupled plasma atomic emission spectrometry. The accuracy of this method was validated by analyzing GBW07605 certified reference material. The results indicated that the distributions of element contents were varied over a wide range in the specimens tested. The decreasing sequence of average element content expressed as dry weight was presented as follows: calcium (1740–22,246 µg/g dry weight), magnesium (634–6367 µg/g dry weight), iron (52.8–5707 µg/g dry weight), barium (9.19–465 µg/g dry weight), zinc (10.7–82.1 µg/g dry weight), strontium (8.25–69.8 µg/g dry weight), copper (4.10–36.6 µg/g dry weight), chromium (0.26–13.3 µg/g dry weight), nickel (0.57–14.7 µg/g dry weight), and cadmium (0.11–2.66 µg/g dry weight). The element contents of samples were different depending on several species. However, the accumulations of toxic elements (cadmium, chromium, and nickel) were above the international safety standards limit in most samples. Principal component analysis generated three principal components that explained 77% of the total variance in the data. Similar samples may get together by cluster analysis and could correspond to the result of principal component analysis.