Quantification of Trans-resveratrol in Red Wines Using QuEChERS Extraction Combined with Liquid Chromatography-Tandem Mass Spectrometry.

Resveratrol is one of representative ingredient in red wine, but its quantification is a challenge because of a complex and abundant matrix. In this study, two sample pretreatments, direct dilution and QuEChERS extraction, coupling LCMS analysis were examined for resveratrol quantification. Similar recoveries of 106.4 to 93.7% were obtained for direct dilution and QuEChERS, respectively. With the aid of condition optimization, QuEChERS extraction could concentrate the resveratrol from red wines to improve the detection sensitivity with a LOD value of 2.5 ng/mL, which is four-times greater than the direct dilution approach. As a result, the QuEChERS method can provide a high linearity within the concentration range of 5 - 500 ng/mL, in which direct dilution produced the linear calibration curve within the concentrations of 25 - 500 ng/mL. A high consistency was obtained for both approaches in which intra-day precisions were within 0.5 to 7.2% (n = 3), and the inter-day precisions were within 7.8 to 16.0% (n = 9). Overall, the sample pretreatment of QuEChERS can effectively reduce the matrix effect, which leads LCMS to quantify the low resveratrol abundance of 8.0 ppb in each red wine sample, which is not achieved with the direct dilution approach.