Brasil Marcos A S, Gomes Luiz H, Kamogawa Marcos Y, Basso Luiz Carlos
Center of Nuclear Energy in Agriculture, University of São Paulo. Av. Centenário, 303, P.O. Box 96, CEP: 13400-970 Piracicaba, SP, Brazil.
Luiz de Queiroz College of Agriculture, University of São Paulo, Av. Pádua Dias, 11, CEP: 13418-900 Piracicaba, SP, Brazil.
J Microbiol Methods. 2020 Oct 15;178:106085. doi: 10.1016/j.mimet.2020.106085.
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 R = 0.999 and RSD = 3.8% and results in agreement with those obtained by the distillation-densitometry official method.
测定发酵底物中的乙醇含量是监测蒸馏酒样品生产过程的一个重要参数。其含量的准确测量对生产过程的盈利能力有直接影响。在本研究中，提出了一种扩散微蒸馏装置（DMDD），可直接测定发酵或蒸馏酒样品中的乙醇。DMDD由一个装有重铬酸钾和硫酸试剂溶液的5 mL塑料试管组成，该试管插入另一个装有样品的50 mL聚乙烯管中。将这套装置在80℃的水浴中加热15分钟，使乙醇扩散，乙醇与试管中含有的受体溶液发生反应。氧化反应产生的铬（III）在589 nm处用分光光度法进行定量。所提出的方法线性范围在1%至12%（v/v）之间，R = 0.999，相对标准偏差（RSD）= 3.8%，结果与蒸馏密度法官方方法所得结果一致。
