Rapid Method for the Determination of the Stable Oxygen Isotope Ratio of Water in Alcoholic Beverages
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- 作者：Daobing Wang ; Qiding Zhong ; Guohui Li ; Zhanbin Huang
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2015
- 出版时间：October 28, 2015
- 年：2015
- 卷：63
- 期：42
- 页码：9357-9362
- 全文大小：336K
- ISSN：1520-5118
文摘
This paper demonstrates the first successful application of an online pyrolysis technique for the direct determination of oxygen isotope ratios (未18O) of water in alcoholic beverages. Similar water concentrations in each sample were achieved by adjustment with absolute ethyl alcohol, and then a fixed GC split ratio can be used. All of the organic ingredients were successfully separated from the analyte on a CP-PoraBond Q column and subsequently vented out, whereas water molecules were transferred into the reaction furnace and converted to CO. With the system presented, 15鈥?0 渭L of raw sample was diluted and can be analyzed repeatedly; the analytical precision was better than 0.4鈥?(n = 5) in all cases, and more than 50 injections can be made per day. No apparent memory effect was observed even if water samples were injected using the same syringe; a strong correlation (R2 = 0.9998) was found between the water 未18O of measured sample and that of working standards. There was no significant difference (p > 0.05) between the mean 未18O value and that obtained by the traditional method (CO2鈥搘ater equilibration/isotope ratio mass spectrometry) and the newly developed method in this study. The advantages of this new method are its rapidity and straightforwardness, and less test portion is required.