Inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectrometer (ICP-OES)-based discrimination for the authentication of tea

Multielement and stable isotopes analysis combined with chemometrics as a potential tool for first authenticity discrimination of teas. Eighty-four statistically significant elements and stable isotopes from Chongqing tuo tea with 4 formulations were determined using ICP-MS and ICP-OES. Four chemometrics were used to build discrimination models.The discrimination of PLS-DA and LDA were better than that of HCA and PCA. 114Cd, 95Mo, 85Rb, Co, 133Cs and P were the most important markers for successful authenticity discrimination of teas. Under the validation by cross-validation, test sets and blind data sets, the precisions of prediction of the PLS-DA and LDA were not less than 90%. The LDA performs best, with precisions of prediction of 100%. This study helps to promote the application of fingerprint technology of multi-elements and stable isotopes in combination with chemometric analysis as a very promising tool for a worldwide inspection of the authenticity of teas.