? LGR的專利技術—利用腔增強激光吸收光譜法,記錄高吸收光譜,能夠精確的測量葡萄酒中的同位素比值。LGR擁有專業(yè)的光譜污染標識軟件(軟件測量植物水的精確數(shù)據(jù)在權威期刊上發(fā)表過),這使得儀器可以測量葡萄酒中的甲醇和乙醇污染物,從而得到可靠的同位素比值數(shù)據(jù)。
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Laser-based measurements of 18O/16O stable isotope ratios (δ18O) in wine samples
應用LGR液態(tài)水穩(wěn)定同位素分析儀測量葡萄酒中的穩(wěn)定同位素比值18O/16O和δ18O
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Manish Gupta1 ? ?J Brian Leen1 ? ?Elena Simone ? ?Franklin Berman1 ? ?Aldo Ciambotti2
1Los Gatos Research, Mountain View, CA, USA;
2Consiglio per la Ricerca e la Sperimentazione in Agricoltura, Centro di Ricerca per l’Enologia, Asti, Italy
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Abstract:?Wine counterfeiting is an international, multi-billion dollar issue, with some estimates suggesting that up to 5% of wines sold at auctions or secondary markets are fraudulent. Isotope ratio mass spectrometer (IRMS) measurements of the 18O/16O stable isotope ratio (δ18O) of water-in-wine have been used for wine authentication; however, these analyses are time-consuming and costly. In this preliminary study, off-axis integrated cavity output spectroscopy (OA-ICOS) is used to quantify δ18O in wines. This laser-based method has been extensively used to study water isotopes for hydrological and medical applications. Recently, the development of a spectral contaminant identifier (SCI) has extended the application of these OA-ICOS analyzers to contaminated water samples (eg, plant, soil, and leaf waters). Here, we utilize OA-ICOS with the SCI to characterize wine samples (9%–15% ethanol), and show that the laser-based instrument provides a δ18O measurement precision of ±0.07‰ (1σ) and agrees with IRMS to within ±0.63‰ (1σ). Moreover, by training the SCI on isotopically-characterized wines, the agreement with IRMS improves to within ±0.30‰ (1σ). The utility of the instrument is demonstrated by measuring watered and mixed wines. The method presented here can be readily extended to address other food authentication applications.
Keywords: wine isotopes, wine fraud, counterfeit wines, OA-ICOS
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查看原文:Laser-Based Measurements of 18O16O Stable Isotope Ratios in Wine Samples