Multi-element analysis of Baijiu (Chinese liquors) by ICP-MS and their classification according to geographical origin

Objectives: Investigating the element profiles of Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Rb, Sr, Ag, Cd, Cs, La, Pr, Nd, Sm, Eu, Gd, Pb, Th, and U of Baijiu (Chinese liquors), and setting up their classification according to geographical origin. Materials and Methods: Twenty-eight Chinese liquors from Shandong, Guizhou, and Sichuan provinces were analyzed by inductively coupled plasma mass spectrometry with the aid of matrix matching, online internal calibration, and direct injection to determine the concentrations of the aforementioned 26 elements. Multivariate statistical analysis, based on the contents of elements in the liquors, was applied to differentiate the liquors from different origins. Results: Both the cluster analysis based on 11 elements and the discriminant analysis based on 5 elements can separate the liquors of Shandong Province from others. A leave-one-out cross test of the discriminant analysis data resulted in 100 per cent accuracy regarding the recognition ability and prediction ability for the liquors from Shandong Province, and an overall 75.0 per cent accuracy of its prediction for all the 28 total liquors. Limitations: The liquors of Guizhou and Sichuan provinces can not be differentiated successfully. Conclusions: The liquors produced in Shandong Province can be differentiated in a great extent from Guizhou and Sichuan provinces based on the multivariate statistical analysis of the concentration of elements in liquors, while those of Guizhou and Sichuan provinces can not be differentiated successfully due to their geographical adjacency.