[Direct analysis of 38 polyphenols in wine by ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry].

Wine has been described previously as a rich source of polyphenols. However, an accurate screening of its complete phenolic profile is still lacking. In the present work, the analysis of 38 polyphenols in wine using ultra high performance liquid chromatography-linear ion trap/orbitrap high resolution mass spectrometry (UPLC-LTQ/Orbitrap MS) was explored. Wines were directly detected. The sample was loaded onto a Thermo Hypersil Gold C18 column (100 mmx 2.1 mm, 1.9 µm) using a gradient elution of acetonitrile/water containing 0. 1% (v/v) formic acid for the separation. UPLC-LTQ/Orbitrap mass spectrometer acquired full scan MS date for quantification, and data dependent MS2 product ion spectra for identification and/ or confirmation. The regression coefficients (R2) for the calibration curves (two orders of magnitude up to the lowest calibration level) in the study were ≥ 0.99. The limits of detection for the 38 compounds were 0.002-0.50 mg/kg. The average recoveries at three spiked levels were in the range of 90%-102% with the relative standard deviations (RSDs) of 0.51%-2.56%. Mass errors were always ≤ 5 ppm. This procedure was then successfully applied to the analysis of the polyphenols in wines.

[Fast screening of the artificial dyes in wine by liquid chromatography/hybrid linear ion trap-orbitrap mass spectrometry].

A fast screening method was established for the simultaneous determination of 15 water-soluble artificial dyes in wine by liquid chromatography/hybrid linear ion trap orbitrap mass spectrometry (LC/LTQ-orbitrap MS) based on a self-established mass spectral database. The confirmations of these target dyes were processed by the accurate mass numbers, and the MS(2) spectra marching to the self-established mass spectral database. The dyes in wine were purified by an anion-exchange column and separated by a BEH Phenyl column, then identified and quantified by LTQ-orbitrap MS. The results showed that the method detection limits of the target compounds were ranged from 0.00040 to 0.18 mg/L, and the average recoveries of the 15 compounds spiked at three concentrations were in the range of 43.1% - 127% with the relative standard deviations less than 10%. The spiked sample had the matching scores higher than 98% to the second order mass spectra of the standard compounds in the database. The method is also suitable for screening the 15 dyes in wine without reference standards.

A geographical discrimination of Shanxi extra aged vinegars using polyalcohols as the discriminators.

A discrimination method based on polyalcohol determination was developed for authenticity of protected geographical indication (PGI) vinegars-Shanxi extra aged vinegar (SVs) in China. Six polyalcohols in vinegars including erythritol, arabitol, xylitol, inositol, mannitol, and sorbitol were selected as the PGI discriminators. GC/MS was used to analyze the polyalcohols in the SVs, Zhenjiang vinegars (ZVs), Kazuo aged vinegars (KVs), and other non-geographical indication protected vinegars (NVs). SVs can be distinguished from KVs by the chemical markers mannitol and sorbitol, although the production processes for both types of vinegars are similar. Principal component analysis (PCA) was used to distinguish SVs from ZVs and NVs. The differences among the three kinds of vinegars shown by PCA results may be due to the higher erythritol content in SVs, and the inositol and mannitol in ZVs. This study also found that the amount of polyalcohols in Chinese vinegars increases with the acidity value only, regardless of the aging time. The overall results indicated that the polyalcohols can be practicable discriminators for SV discrimination.