Cabañero Ana I, Recio Jose L, Rupérez Mercedes
Laboratorio Arbitral Agroalimentario, Ministerio de Medioambiente y Medio Rural y Marino, Ctra. Coruña Km 10,700, 28023 Madrid, Spain.
Rapid Commun Mass Spectrom. 2008 Oct;22(20):3111-8. doi: 10.1002/rcm.3711.
Two new procedures for wine ethanol 13C/12C isotope ratio determination, using high-performance liquid chromatography and gas chromatography isotope ratio mass spectrometry (HPLC/IRMS and GC/IRMS), have been developed to improve isotopic methods dedicated to the study of wine authenticity. Parameters influencing separation of ethanol from wine matrix such as column, temperature, mobile phase, flow rates and injection mode were investigated. Twenty-three wine samples from various origins were analyzed for validation of the procedures. The analytical precision was better than 0.15 per thousand, and no significant isotopic fractionation was observed employing both separative techniques coupled to IRMS. No significant differences and a very strong correlation (r = 0.99) were observed between the 13C/12C ratios obtained by the official method (elemental analyzer/isotope ratio mass spectrometry) and the proposed new methodology. The potential advantages of the developed methods over the traditional one are speed (reducing time required from hours to minutes) and simplicity. In addition, these are the first isotopic methods that allow 13C/12C determination directly from a liquid sample with no previous ethanol isolation, overcoming technical difficulties associated with sample treatment.
已开发出两种使用高效液相色谱和气相色谱同位素比率质谱法（HPLC/IRMS和GC/IRMS）测定葡萄酒乙醇13C/12C同位素比率的新方法，以改进用于葡萄酒真伪研究的同位素方法。研究了影响从葡萄酒基质中分离乙醇的参数，如色谱柱、温度、流动相、流速和进样模式。分析了23个来自不同产地的葡萄酒样品以验证该方法。分析精度优于千分之0.15，并且在将两种分离技术与IRMS联用的情况下未观察到明显的同位素分馏。通过官方方法（元素分析仪/同位素比率质谱法）获得的13C/12C比率与所提出的新方法之间未观察到显著差异，且具有很强的相关性（r = 0.99）。所开发方法相对于传统方法的潜在优势在于速度（将所需时间从数小时减少到数分钟）和简便性。此外，这些是首批无需预先分离乙醇即可直接从液体样品中测定13C/12C的同位素方法，克服了与样品处理相关的技术难题。
