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A simple sample preparation approach employing the dispersive pipette extraction (DPX) technique is proposed to determine twelve polyphenols, including phenolic acids and flavonoids in wines, followed by identification and quantification by LC-MS/MS. The extraction parameters, including sample volume and pH, salting out effect, time and cycles of extraction and desorption, and desorption solvent were optimized using univariate and multivariate designs. The analytical performance was satisfactory, with determination coefficients greater than or equal to 0.9877, precisions with values lower than 20 %, and recoveries ranging from 87 to 114 %. The applicability of the method was evaluated in red wine. The major compounds determined in the sample were (-)-epicatechin (23.5 mg L -1 ), (+)-catechin (19.2 mg L -1 ), and myricetin (14.6 mg L -1 ). The green character of the analytical procedure and the sample preparation step were evaluated by three analytical metrics., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The aim of this study was to characterise the bioactive compounds in mate (Ilex paraguariensis St. Hil) extract and in concentrated mate extract obtained by nanofiltration (NF). Also, the impact of NF on the antioxidant activity of both mate extracts was evaluated in vitro and using eukaryotic cells of Saccharomyces cerevisiae (yeast assay). The results showed a significant increase in the contents of total phenolics (338%), chlorogenic acid (483%), theobromine (323%), caffeine (251%), chlorophyll (321%), condensed tannins (278%) and saponins (211%) in the concentrated mate extract. The concentrated mate extract showed higher in vitro antioxidant activity than the mate extract. According to the results obtained, it can be stated that the use of nanofiltration membrane is a valid approach for the concentration of biologically active compounds in aqueous extract of mate., (Copyright © 2013 Elsevier Ltd. All rights reserved.)