Smartphone application for methanol determination in sugar cane spirits employing digital image-based method

• Autor(a) principal: Franco, Mathews de Oliveira Krambeck
• Data de Publicação: 2016
• Outros Autores: Suarez, Willian Toito, Maia, Matheus Valentin, Santos, Vagner Bezerra dos
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://dx.doi.org/10.1007/s12161-016-0777-y; http://www.locus.ufv.br/handle/123456789/22535
• topic: Spot test; Digital image analysis; Methanol; Sugar cane spirits; Cachaça; Food analysis; Food contamination

A simple, accurate, and low-cost analytical procedure for methanol determination in sugarcane spirits (cachaça) employing analysis of digital images is presented. A portable system with cheap materials and lighting system to obtain images from a smartphone was built and an RGB system was used for analytical purposes. The reaction for determination of methanol in beverages consists in methanol oxidation to methanal, and consequent formation of a violet chromophore in the presence of chromotropic acid on heating in an oven at 80 °C for 15 min. From the system optimization, analytical curves that showed good linearity for the green channel (from RGB) was built, with regression coefficient (R^ 2) of 0.998. Relevant matrix effect in the samples was not verified, since the recovery percentage ranged from 83 to 110%. The results of methanol concentration in six cachaça samples obtained by the developed method were compared with using the spectrophotometric method with a confidence level of 95% (n = 3). The developed method has some economic and environmental benefits, since it has low reagent consumption with 800 μL per measured spot, as well as, it presents cheap and handle-easy devices, which encourages the quality control of this toxic and undesirable contaminant for smallholders and industries on production of sugar cane spirits.