不同海拔区间白茶化学元素特征分析及产地判别OA北大核心CSTPCD

This study aimed to investigate the feasibility of mineral elements and rare earth elements in identification of white tea origin.The mineral elements and rare earth elements of white tea produced in Zhenghe county at different altitudes were analyzed using inductive plasma coupled with mass spectrometry and chemometrics tools to screen the index elements and construct the discriminant models.The contents of K,Ca,Mg and Mn in Low altitude intervals of Fu'an big white tea(LWT)were extremely significantly(P<0.01)or significantly(P<0.05)higher than that of the high altitude intervals of Fu'an big white tea(HWT).However,the contents of Na,As,Cd,Sn,Se in LWT were extremely significantly lower than that of HWT(P<0.01),Ce,Y,La,Lu,Pr,Sm,Tb,Tm and Nd in LWT were extremely significantly(P<0.01)or significantly(P<0.05)lower than that of HWT.Five characteristic mineral elements,including Ca,K,Cd,Pb and Sn,were selected by step discriminant analysis.The overall discriminant accuracy of initial and cross verification was 91.7%and 88.3%,respectively.Two rare earth elements,including Eu and Tb,were screened,and the discriminant accuracy of both the overall initial and cross validation was 91.7%,respectively.The overall initial and cross validation discriminant accuracy of the seven special chemical elements were 98.3%and 96.7%,respectively.The discriminant prediction index value analyzed by orthogonal partial least squares discriminant analysis followed the order of 16 mineral elements(0.619)<5 characteristic mineral elements(0.678)<15 rare earth elements(0.682)<2 characteristic rare earth elements(0.734)<7 characteristic chemical elements(0.807).When seven characteristic chemical elements were used as indexes,the LWT and HWT had a better identification effect.Therefore,combination of mineral elements and rare earth elements was effective in the identification of white tea produced in small scale areas of different altitudes.This study provides a scientific basis for the establishment of chemical element database and the identification of origin tracing of special tea in Fujian Province.