Automated solid-phase extraction for sample preparation followed by high-performance liquid chromatography with diode array and a mass spectrometric detection for analysis of resveratrol derivatives in wine
ABSTRACT A method has been developed for the simultaneous determination of resveratrol in all its forms (free isomers and glycosylates) in wines by high-performance liquid chromatography with diode array and mass spectrometric detection. Prior to injection into the column, preconcentration of the sample by automated solid-phase extraction is carried out. In the detection by UV absorption, quantitation was carried out at 280 and 305 nm, and in detection by mass spectrometry, quantitation was performed in the selected ion monitoring mode at m/z 228 and at m/z 238. A comparative study between both detection systems was carried out.
- SourceAvailable from: Enrique J. Martinez de la Ossa
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- "The pressing of this grape produces approximately 15–20% of pomace, and this is usually used as a fertilizer. Resveratrol has not been detected in the Jerez wines (Domínguez et al., 2001) or has been detected at very low concentrations (0.03 mg/L) (Martínez-Ortega et al., 2000). However , Roldán et al. (2003) detected its presence in the Palomino fino grape. "
ABSTRACT: Resveratrol is a phenolic compound that is present in grapes and has significant benefits for human health. The development of methods to obtain concentrates of this compound is currently a major challenge in the food industry. In the work described here, resveratrol from grape seeds, stems, skin and pomace of the Palomino fino grape variety was extracted by supercritical carbon dioxide extraction. The effect of pressure (100, 400 bar), temperature (35, 55 °C) and the addition of modifier (5% v/v of ethanol) was evaluated to identify optimal resveratrol extraction from this by-product. Extraction yields and concentrations of resveratrol in the extracts were determined. The best results were obtained on working at high pressure and low temperature using 5% v/v ethanol as a co-solvent.Journal of Food Engineering 01/2010; 96(2-96):304-308. DOI:10.1016/j.jfoodeng.2009.08.002 · 2.58 Impact Factor
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- "The trans-resveratrol can be analysed directly (Abril et al., 2005; Vitrac et al., 2002) or after pre-treatment of wine samples in order to increase its content. Liquid–liquid extraction (Wang et al., 2002) and solid-phase extraction (SPE) (Rodríguez-Delgado et al., 2002; Domínguez et al., 2001; Malovaná et al., 2001; Gamoh and Nakashima, 1999) have been used in sample preparation for concentration and cleaning purposes. "
ABSTRACT: Liquid chromatography and mass spectrometry conditions were developed in order to identify trans-resveratrol in sweet fortified Muscatel wines from Setúbal region (Portugal). Diode array, fluorescence and electrochemical detectors were used for quantitation purposes. The detection and quantitation limits for each detection mode were: 0.02 and 0.06mgL−1 for UV–vis, 0.01 and 0.03mgL−1 for fluorescence and 0.45 and 1.35mgL−1 for electrochemical. Repeatibility (n=6) expressed as the relative standard deviation of peak areas for a standard solution of trans-resveratrol (1.75mgL−1) was 0.5% for fluorescence and 1.5% for UV–vis and electrochemical detection modes. Samples collected at one representative producer, during the winemaking process, were injected without pre-treatment and the quantitation of trans-resveratrol was carried out using fluorimetric detection. The trans-resveratrol content decreased slightly along the winemaking process and the concentrations ranged from 0.22±0.02 to 0.16±0.02mgL−1.After maturation stages, trans-resveratrol contents in wines collected at different producers were compared: values obtained range from 0.13±0.02 to 0.38±0.03mgL−1. The trans-resveratrol contents in commercially available wines from the same producers were lower.Journal of Food Composition and Analysis 12/2008; 21(8):634-643. DOI:10.1016/j.jfca.2008.04.007 · 2.26 Impact Factor
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ABSTRACT: form only given. We report the results of temperature (T) dependent dc conductivity (/spl sigma//sub dc/), thermopower (S), microwave dielectric constant (E/sub mw/ and EPR studies for camphor sulfonic acid doped polyaniline (PAN-CSA) and its methyl ring-substituted derivative poly(o-toluidine) (POT-CSA) fibers, and contrast them with HCI doped samples (PAN-HCI and POT-HCI). For POT-HCl fibe, /spl sigma//sub dc/(295K) ~ 0.02 S/cm and /spl sigma//sub dc/(T) x exp[-(T/sub o/(/T)/sup -1/2/] with T/sub o//spl cong/3.8 x 10/sup 4/ K, very similar POT-HCl powder./sup 1/ In contrast, for POT-CSA fiber, /spl sigma//sub dc/(295K) ~ 10 S/cm and /sol sigma//sub dc/(T) shows much weaker T dependence with an effective T/sub o/ //spl cong/ 350 K. POT-CSA fiber also shows much higher /spl epsi//sub mw/ (T) and dramatically different thermopower than POT-HCl with S = A + BT, where A 0, indicating that POT-CSA fiber is much closer to localization-delocalization boundary than POT-HCl. The results for PAN-CSA fiber are very similar to those for PAN-CSA films/sup 2/ with the presence of some poorer conducting linkages. Supported in part by OSU Center for Materials Research and US ONR