Multi-element analysis of three Codonopsis Radix varieties in China and its correlation analysis with environmental factors

Abstract

The feasibility of using chemometric techniques associated with multi-element analysis for the classification of three varieties of Codonopsis Radix samples was investigated, and the correlation between environmental factors and metal element content was further explored. It was found that R. Codonopsis was a good source of potassium (average content of 9420 μg/g), magnesium (average content of 1590 μg/g), calcium (average content of 388 μg/g) and iron (average content of 333 μg/g). The statistical analysis results indicated that twenty-two elements content (K, Ca, Mg, Fe, Se, Na, Zn, V, Cu, Cr, Mn, Ni, Co, Sr, Pb, Cd, As, Hg, Al, Ba, Tl and U) were significantly different among three R. Codonopsis varieties, hence it was possible to discriminate R. Codonopsis according to their varieties by LDA (correct classification rate of 98.6 % and cross-validation rate of 95.9 %). In addition, the correlation analysis results indicated that the relative humidity showed significantly negative correlation with essential elemental content such as K, Mg, Ca and Se (correlation coefficients ranged from -0.321 to -0.564, p < 0.05); the annual average precipitation exhibited significantly positive correlation with toxic elemental elements such as As, Cd, Pb and Hg (correlation coefficients ranged from 0.266 to 0.897, p < 0.05).