Determination of mineral elements of wild and cultivated Wolfiporia extensa collected from Yunnan

In order to study the distribution characteristics of mineral elements in Wolfiporia extensa from Yunnan Province,12 elements of Fe,Mn,Cu,Zn,Co,Li,V,Ba,Cr,As,Cd and Pb in wild and cultivated W.extensa from 15 origins were determined using inductively coupled plasma mass spectrometer( ICP- MS) method. The quantitative results were analyzed by principle component analysis( PCA) and correlation analysis using SPSS 21.0 software.The results showed that the correlation coefficients( r) of linear regression equations were all higher than 0.999 and the detection limits were in range of 0.009~1.035 μg / L.Besides,the measured values of national standard reference of spinach( GBW 10015) and shrub leaves( GBW 07603) were within the standard range,demonstrating that this method could be used for the determination of mineral elements of W. extensa accurately and reliably. The results showed that the test samples were rich in mineral elements and the content of Fe,Mn,Co,V and Cr in cultivated W.extensa were higher than that of the wild ones.In addition,the contents of Fe in wild and cultivated sclerotia were31.8~108.3 and 49.7~805.6 mg / kg,and the contents of Mn were 5.59~35.6 and 12.9~67.7 mg / kg,respectively. The average amounts of Cu,Zn and Ba were 1~10 mg / kg.The average amounts of Co,Li,V,As,Cd,Pb and Cr were all less than 1.0 mg / kg and the contents of other toxic heavy metals,such as As( < 0.16 mg / kg),Cd( < 0.03 mg /kg),Pb( < 0.35 mg /kg),were all lower than the maximum limit of the national food safety standard,World Health Organization( WHO) and Chinese Pharmacopoeia( 2015 edition).The results of PCA showed that the first principal component factor could represent 49.060% total variance contribution.The loading values of Mn,Fe,V,Li,As and Cr were higher than that of other elements,which could be regard as the characteristic elements.Correlation analysis displayed that 14 pairs of mineral elements showed significant( p < 0.05) or high significant correlation( p < 0.01) and these elements had intrinsical relationships in the growth process in W.extensa.