Abstract: In this study, we discriminated the geographical origin of Hunan Anhua dark tea by using inductively coupled plasma mass spectrometry (ICP-MS) combined with chemometrics. Quantitative analysis of 48 elements such as B, Li and P was carried out in Hunan Anhua dark tea and those from other geographical origins by ICP-MS, and an elemental fingerprint for Anhua dark tea was obtained. The element distribution in dark teas from different geographical origins was evaluated by characteristic analysis, discriminant analysis, principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). In the PCA and the PLS-DA score plots, Anhua dark tea was effectively discriminated from those from other regions. Nineteen elements including Li, Pb and Ga were significantly different between Anhua dark tea and those from other regions. Seven key elements (Li, Pb, Ga, Ce, Rb, Cs and Na) were introduced into?the discriminant?analysis?model. The correct discrimination rate of the mode was 100% and 98%?in back substitution and cross-validation test, respectively. The results showed that the elemental fingerprint could be used for the geographical origin discrimination of Anhua dark tea.

Key words: inductively coupled plasma mass spectrometry; elemental fingerprint; principal component analysis; partial least squares discriminate analysis; Anhua dark tea; discrimination