Investigação de novas metodologias de análise e controle de qualidade para o ácido tartárico

Abstract

Tartaric acid is an organic acid, naturally contained in some fruits, especially grape and tamarind. It plays an important role in the wine industry and it is an important additive applied in several sectors. There are essentially three methods of obtaining tartaric acid: natural as a byproduct of wine, chemical synthesis and biotechnological synthesis. Information about production method and geographic origin of this product is relevant to avoid commercial frauds and mislabeling, but also to address safety issues to consumers. The objective of this work wasto characterize tartaric acid in order to establish parameters of qualification and traceability. Initially several analytical techniques, such as UPLC, NMR and FT-IR, were applied to identify presence of impurities and/or traces from synthetic route of tartaric acid. However, the dataobtained was not promising, due to high purity of the products. Then isotope-ratio mass spectrometry technique was applied and distinguished isotopic profiles of the samples were obtained. IRMS associated with different multivariate statistics methods were able to classify tartaric acid samples by production and geographic production of tartaric acid. The combination of both techniques allowed the correct classification of 100% of the samples according to their production method and continent of origin. Four tartaric acid derivatives were also evaluated: potassium bitartrate, metatartaric acid, calcium tartrate and, potassium sodium tartrate. Isotopic analysis of derivatives were compared to isotopic profile of tartaric acid, with notorious resultsfor potassium bitartrate and metatartaric acid. Even though further studies including a larger number of samples in each group are needed in order to validate these findings, we can conclude that isotopic analysis associated with multivariate analysis should be considered as an important methodology for the study and quality control of tartaric acid and its derivatives.