Nyseos, 2 place Pierre Viala, 34060 Montpellier Cedex 1, France.
Food Chem. 2015 Jun 15;177:152-7. doi: 10.1016/j.foodchem.2015.01.027. Epub 2015 Jan 9.
For the first time, we proposed a high-throughput method to quantify glutathione in grapes, musts and wines for all grape varieties using Stable Isotope Dilution Assay (SIDA). Indeed, the use of SIDA as a quantification method is essential to overcome the chemical instability of glutathione. In practice, glutathione was derivatized in-situ with N-ethylmaleimide to block the cysteine residue and to enhance its lipophilic properties. After quenching with acetic acid, samples were directly analyzed by LC-MS/MS (run of 13 min) in Multiple Reaction Monitoring mode using labeled glutathione as internal standard. The validation according to the International Organization of Vine and Wine recommendations demonstrated the high sensitivity (LOD=45 μg L(-1)), accuracy (recovery=112%) and intermediate reproducibility (RSD=12%) of the method. This high-throughput method that requires only 1 mL of matrix, allowed us to analyze 70 samples per day for a moderate cost.
我们首次提出了一种高通量方法，使用稳定同位素稀释分析（SIDA）定量分析所有葡萄品种的葡萄、葡萄汁和葡萄酒中的谷胱甘肽。实际上，使用 SIDA 作为定量方法对于克服谷胱甘肽的化学不稳定性至关重要。在实践中，谷胱甘肽与 N-乙基马来酰亚胺原位衍生化，以封闭半胱氨酸残基并增强其亲脂性。用乙酸淬灭后，样品直接通过 LC-MS/MS（运行时间 13 分钟）在多反应监测模式下进行分析，使用标记的谷胱甘肽作为内标。根据国际葡萄与葡萄酒组织的建议进行验证，证明了该方法具有高灵敏度（LOD=45μg L(-1)）、准确性（回收率=112%）和中等重现性（RSD=12%）。这种高通量方法仅需 1 毫升基质，每天可分析 70 个样品，成本适中。
