Determinação de flavonóides e resveratrol em vinho empregando cromatografia de fluxo turbulento-LC-MS

Abstract

Wine is known for its favorable biochemical properties such as antioxidant, anticarcinogenic and anti-inflamatory properties. Many of these properties can be assigned to flavonoids and resveratrol. Wine is known to contain high amounts of interferences, such as proteins and lipids complicating analysis of flavonoids and other compounds of interest. Turbulent Flow Chromatography (TFC) on-line coupled to Liquid Chromatography Mass Spectrometry (LC-MS) was used to analyze flavonoids present in different types of wines. The TFC sample pretreatment is based on the fast removal of high molecular weight compounds and the removal of low molecular weight polar interferences. After the sample pretreatment, the TFC column is on-line coupled to LC-MS and a gradient is started to elute the trapped compounds and separate these in the LC-MS. The method proved to be fast, non-laborious, robust and sensitive. The feasibility of the method was tested on several red, white and rosé wines. Interday and intraday precision for all wines and concentrations were calculated to be < 12% and < 18%, respectively. The method proved to be linear for all investigated compounds and matrices in the range of 0.05 to 2 mg L-1 (r2 > 0.99). Moreover resveratrol showed also linearity (r2 > 0.99) in higher range (1 to 50 mg L-1). The LOD for the compounds in red wine ranged from 0.004 to 0.022 mg L-1, in white wine ranged from 0.002 to 0.021 mg L-1 and in rosé wine ranged from 0.003 to 0.034 mg L-1. Quantitation of resveratrol was possible using standard addition procedure, since resveratrol was present in the sample. Red wine showed a higher amount of resveratrol (4 mg L-1), compared to rosé and white wine which was 10-fold lower. Moreover, the different red wines contained also different amounts of resveratrol. The presented method may be an useful tool to study other analytes in difficult matrices, such as compounds of interest in food, drinks and biological samples.