KAI Jianrong, WANG Caiyan, SHI Xin, LI Caihong, YANG Chunxia, WANG Xiaojing
Inductively coupled plasma mass spectrometry (ICP-MS) was used to trace and determine the contents of 55 mineral elements in different maturation stages of Lycium barbarum from Zhongning in Ningxia province. The results showed that the contents of 55 elements in Zhongning Lycium barbarum varied greatly. In which Cu, Co, B, Mg, Mn, Mo, Ca, Cd, Cr, Ni, Ba, Sr, Rb, Ti, W and Ga showed a decreasing trend in five maturation stages, while Fe, Zn, V, Pb, As, Hg, Sb, Tl, La, Ce, Nd, Y, Pr, Eu, Yb, Dy, Er, Gd, Sm, Tb, Ho, Tm, Lu, Sn, Bi, Be, Li, Cs, Zr, Nb, Ag, Ta, Ge showed a trend of decreasing at first and then increasing. In addition, Sc, Pd, Hf, Zr and Pt were firstly increased and then decreased. The rare earth elements showed the characteristics of enrichment of light rare earth elements and deficiency of heavy rare earth elements. The heavy metals of Zhongning Lycium barbarum did not exceed the national standard. The contents of 55 elements in 5 mature stages of Zhongning Lycium barbarum were analyzed by Partial Least Squares Discrimination Analysis, and 2 principal components were extracted with the cumulative variance contribution rate of 80.9%. The first principal component and the second principal component scores of different mature stages of Lycium barbarum could be well distinguished from the samples. Twenty-two elements, including Sc, Li, Zn, Ta, Be, La, Se, Sb, Lu, Pt, Ni, Ir, Sr, Hg, Mo, Bi, Pb, W, Hf, Yb, Pd and Sn, were screened out as effective distinguishing indexes for different maturation stages of Zhongning Lycium barbarum. The absorption and accumulation of most mineral elements had “time difference”.
