Product categories of Remove Installation Reset Tools, we are specialized manufacturers from China, Remove Installation Reset Tools, Clean Up Tool suppliers/factory, wholesale high-quality products of Removal Tool R & D and manufacturing, we have the perfect after-sales service and technical support. Look forward to your cooperation! The exact quantity of grape sample (stem, skin, pulp, seeds) weighing 1 g during 24 hours was kept in 10 mL of a 60% solution of ethanol. After a fivefold extraction, the solution filtered and quantitatively transferred to a 50 mL volumetric flask. The alcohol was then distilled under vacuum, thereby leaving phenolic compounds in the aqueous phase. From the aqueous phase, they were extracted with ethyl acetate, the resulting phase was dried with sodium sulfate, the ethyl acetate was removed under vacuum and the resulting residue was dissolved in methanol. Prior to the analysis, they were filtered on a 0.45 μm membrane filter. Chromatographic separation was carried out as follows: gradient elution with bidistillate and acetonitrile, aciditated with acetic acid. Total analysis time is no more than 60 minutes. The phenolic compounds were identified using retention times of appropriate standards. For quantification calculation the calibration curves were constructed for the identified compounds. All measurements were made thrice. Chromatograms of some identified phenolic compounds are submitted below (Figures 1-4).