Analysis of some metals in wine by means of capillary electrophoresis. Application to the differentiation of Ribeira Sacra Spanish red wines

Abstract

The content of some metals (Na, K, Ca, Mg, Mn and Li) in a variety of red wines produced in different geographi- cal zones of Galicia was determined in a single analysis by capillary electrophoresis. Data were processed using multivariate supervised and non-supervised chemometric techniques involving cluster analysis, principal component analysis (PCA), linear dis - criminant analysis (LDA), K nearest neighbours (KNN) and soft independent modelling of class analogy (SIMCA). The results obtained have allowed for the categorisation of wine samples according to their origin; the wines with Ribeira Sacra Certified Brand of Origin (CBO) can be differentiated from the wines of two other CBO from Galicia: Ribeiro and Valdeorras. The latter two types of wine are made with the same or similar grape varieties; hence, due to their similar organoleptic properties they a re possible substitutes for the falsification of Ribeira Sacra wines.