This work utilized the simplicity of a so-called membraneless vaporization (MBL-VP) unit as a gas separator for the colorimetric determination of ethanol in alcoholic beverages. A beverage sample with a volume of 1 mL was directly injected into a small container which was hung from a lid inside a closed 40 mL reused glass bottle without pretreatment such as distillation. An acidified potassium dichromate (Cr₂O₇²⁻) acceptor solution, preadded to the glass bottle, was reduced to Chromium (III) ion by the diffusion of vaporized ethanol from the sample. After 5 min, the absorbing solution was collected for colorimetric detection at 590 nm. The unit manually quantifies ethanol in the range 1.0–90% (v/v) with satisfactory interday precision but without matrix effect (recovery 89−109%). The method was validated with the conventional distillation/pycnometer method which showed no significant difference of ethanol contents between those two methods and the declared values of 12 alcoholic beverages, indicating sufficient accuracy. Analyses of alcoholic beverages using this method were successful with benefits of simplicity, cheapness, and less energy consumption.

中文翻译：

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国产无膜汽化气液分离器比色法测定酒精饮料中的乙醇

这项工作利用所谓的无膜汽化 (MBL-VP) 装置的简单性作为气体分离器，用于比色测定酒精饮料中的乙醇。将体积为 1 mL 的饮料样品直接注入一个小容器中，该小容器悬挂在一个封闭的 40 mL 重复使用玻璃瓶内的盖子上，无需进行蒸馏等预处理。酸化的重铬酸钾 (Cr ₂ O ₇ ²⁻) 预先添加到玻璃瓶中的受体溶液通过样品中蒸发的乙醇的扩散还原为铬 (III) 离子。5 分钟后，收集吸收溶液在 590 nm 处进行比色检测。该装置手动量化 1.0-90% (v/v) 范围内的乙醇，具有令人满意的日间精度，但没有基质效应（回收率 89-109%）。该方法经传统蒸馏/比重瓶法验证，两种方法的乙醇含量与12种酒精饮料的申报值无显着差异，具有足够的准确性。使用这种方法对酒精饮料进行分析是成功的，具有简单、便宜和能耗低的优点。