The determination of ethanol in fermented substrates is an important parameter for monitoring the production of distilled beverage samples. The correct measurement of its content has a direct impact on the profitability of the process. In this work, a diffusive micro-distillation device (DMDD) is proposed that allows the determination of ethanol directly in the fermented or distilled beverages samples. The DMDD consists of a 5 mL plastic test tube containing a reagent solution of potassium dichromate and sulfuric acid, inserted into another 50 mL polyethylene tube containing the sample. This set is heated in a water bath for 15 min at 80 °C, providing the ethanol diffusion, which reacts with the receptor solution contained in the test tube. The chromium (III) produced by the oxidation reaction, is spectrophotometrically quantified at 589 nm. The proposed procedure has a linear range between 1 and 12% (v/v) with R² = 0.999 and RSD = 3.8% and results in agreement with those obtained by the distillation-densitometry official method.

发酵底物中乙醇的测定是监测蒸馏饮料样品生产的重要参数。其含量的正确测量直接影响过程的盈利能力。在这项工作中，提出了一种扩散微蒸馏装置（DMDD），可以直接测定发酵或蒸馏饮料样品中的乙醇。 DMDD 由一根装有重铬酸钾和硫酸试剂溶液的 5 mL 塑料试管组成，插入另一根装有样品的 50 mL 聚乙烯管中。该装置在 80°C 水浴中加热 15 分钟，提供乙醇扩散，与试管中包含的受体溶液发生反应。氧化反应产生的铬 (III) 在 589 nm 处进行分光光度法定量。所提出的程序具有 1 至 12% (v/v) 之间的线性范围，其中 R ² = 0.999，RSD = 3.8%，结果与蒸馏密度测定官方方法获得的结果一致。