Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests
Autor(a) principal: | |
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Data de Publicação: | 2013 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Repositório Institucional da UFSCAR |
Texto Completo: | https://repositorio.ufscar.br/handle/ufscar/6565 |
Resumo: | In this work a simple, fast and inexpensive analytical method was developed to carry out in situ determinations of ethanol and sulfite ions in food samples. The method was based on digital images captured by cameras and / or mobile phones, using a proper device for this purpose. Indirect colorimetry was employed, where it was measured the intensity of the light reflected by the solution, employing the RGB color model. The quantification of the analytes was performed by calibration curve method, using image processing software to obtain the numerical values for each one of the three primary colors (red (R), green (G) and blue (B)). In the first procedure, it was determined the ethanol concentration in drinks, obtaining limits of detection (LOD) and quantification (LOQ) of 0.25 and 0.85 %, respectively, with a linear calibration curve in the range from 1 to 20 % v / v (r = 0.999), using the R channel due to better linearity and results in close agreement to the spectrophotometric method used as reference method, with a confidence level of 95 %. The recovery study was carried out in six commercial samples and the recovery percentage ranged between 85.0 and 106%. The sulfite ions were determined in wines, vinegars and juices samples, with limits of detection (LOD) and quantification (LOQ) of 3.3 × 10-5 mol L -1 and 1.0 × 10 -4 mol L-1, respectively, and with a linear calibration curve from 1.0 × 10-4 to 3.0 × 10-3 mol L1 (r = 0.997) using the B channel supplying a good linearity and results in close agreement to the iodometric titration method employed as reference method, at a confidence level of 95 %. The recovery percentage of sulfite in commercial samples ranged between 84.4 and 103%. |
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Benedetti, Luzia Pires dos SantosFatibello Filho, OrlandoÚltima atualização do currículo em 14/03/2011http://lattes.cnpq.br/950275691097893407cd2bca-7667-4d38-b359-2bb4e1224df82016-06-02T20:36:47Z2013-09-132016-06-02T20:36:47Z2013-07-12BENEDETTI, Luzia Pires dos Santos. In situ determination of food analytes employing digital images processing by spot tests. 2013. 94 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2013.https://repositorio.ufscar.br/handle/ufscar/6565In this work a simple, fast and inexpensive analytical method was developed to carry out in situ determinations of ethanol and sulfite ions in food samples. The method was based on digital images captured by cameras and / or mobile phones, using a proper device for this purpose. Indirect colorimetry was employed, where it was measured the intensity of the light reflected by the solution, employing the RGB color model. The quantification of the analytes was performed by calibration curve method, using image processing software to obtain the numerical values for each one of the three primary colors (red (R), green (G) and blue (B)). In the first procedure, it was determined the ethanol concentration in drinks, obtaining limits of detection (LOD) and quantification (LOQ) of 0.25 and 0.85 %, respectively, with a linear calibration curve in the range from 1 to 20 % v / v (r = 0.999), using the R channel due to better linearity and results in close agreement to the spectrophotometric method used as reference method, with a confidence level of 95 %. The recovery study was carried out in six commercial samples and the recovery percentage ranged between 85.0 and 106%. The sulfite ions were determined in wines, vinegars and juices samples, with limits of detection (LOD) and quantification (LOQ) of 3.3 × 10-5 mol L -1 and 1.0 × 10 -4 mol L-1, respectively, and with a linear calibration curve from 1.0 × 10-4 to 3.0 × 10-3 mol L1 (r = 0.997) using the B channel supplying a good linearity and results in close agreement to the iodometric titration method employed as reference method, at a confidence level of 95 %. The recovery percentage of sulfite in commercial samples ranged between 84.4 and 103%.Neste trabalho foi desenvolvido um método analítico simples, rápido e de baixo custo, para realizar determinações in situ de etanol e íon sulfito em amostras de produtos alimentícios. O método utilizado foi baseado em imagens digitais capturadas por câmeras fotográficas e/ou celulares, utilizando um sistema construído para este fim. A técnica utilizada foi a colorimetria indireta, em que foi medida a intensidade de luz refletida pela solução, abordando o modelo de cores RGB. A quantificação dos analitos foi realizada a partir do método da curva de calibração, utilizando um software de tratamento de imagens para se obter os valores numéricos de cada uma das três cores primárias (vermelha (R), verde (G) e azul (B)). No primeiro procedimento foi determinado o teor (em %) de etanol em bebidas, obtendo-se limites de detecção (LD) e de quantificação (LQ) da ordem de 0,25 e 0,85 %, respectivamente, com uma curva analítica linear no intervalo de 1 a 20 % v/v (r = 0,999), utilizado o canal R por ter apresentado melhor linearidade e resultados mais próximos do método espectrofotométrico utilizado como método referência, a um nível de confiança de 95 %. O percentual de recuperação nas amostras comerciais variou entre 85,0 e 106 %. Na sequência, foi determinado sulfito em amostras de vinhos, vinagres e sucos, obtendo-se LD e LQ da ordem de 3,3 × 10−5 mol L−1 e 1,0× 10−4 mol L−1, respectivamente, com uma curva analítica linear de 1,0 × 10−4 a 3,0 × 10−3 mol L−1 (r = 0,997), utilizando o canal B por ter apresentado melhor linearidade e resultados mais próximos do método de referência, baseado na titulação iodométrica, com um nível de confiança de 95 %. O percentual de recuperação de sulfito nas amostras comerciais variou entre 84,4 e 103 %.Financiadora de Estudos e Projetosapplication/pdfporUniversidade Federal de São CarlosPrograma de Pós-Graduação em Química - PPGQUFSCarBRQuímica analíticaImagens digitaisRGBEtanolSulfitoCIENCIAS EXATAS E DA TERRA::QUIMICADeterminação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot testsIn situ determination of food analytes employing digital images processing by spot testsinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesis-1-17a1dec22-4b2d-4dba-8971-ab07f55c7d54info:eu-repo/semantics/openAccessreponame:Repositório Institucional da UFSCARinstname:Universidade Federal de São Carlos (UFSCAR)instacron:UFSCARORIGINAL5404.pdfapplication/pdf1590369https://repositorio.ufscar.br/bitstream/ufscar/6565/1/5404.pdf08f2fb043c3367476be35e4649c5b7b8MD51THUMBNAIL5404.pdf.jpg5404.pdf.jpgIM Thumbnailimage/jpeg8397https://repositorio.ufscar.br/bitstream/ufscar/6565/2/5404.pdf.jpg47010d994f2e8da0fd2c0e207f5d904aMD52ufscar/65652023-09-18 18:31:11.971oai:repositorio.ufscar.br:ufscar/6565Repositório InstitucionalPUBhttps://repositorio.ufscar.br/oai/requestopendoar:43222023-09-18T18:31:11Repositório Institucional da UFSCAR - Universidade Federal de São Carlos (UFSCAR)false |
dc.title.por.fl_str_mv |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
dc.title.alternative.eng.fl_str_mv |
In situ determination of food analytes employing digital images processing by spot tests |
title |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
spellingShingle |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests Benedetti, Luzia Pires dos Santos Química analítica Imagens digitais RGB Etanol Sulfito CIENCIAS EXATAS E DA TERRA::QUIMICA |
title_short |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
title_full |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
title_fullStr |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
title_full_unstemmed |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
title_sort |
Determinação in situ de analitos de interesse alimentício empregando tratamento de imagens digitais de spot tests |
author |
Benedetti, Luzia Pires dos Santos |
author_facet |
Benedetti, Luzia Pires dos Santos |
author_role |
author |
dc.contributor.authorlattes.por.fl_str_mv |
http://lattes.cnpq.br/9502756910978934 |
dc.contributor.author.fl_str_mv |
Benedetti, Luzia Pires dos Santos |
dc.contributor.advisor1.fl_str_mv |
Fatibello Filho, Orlando |
dc.contributor.advisor1Lattes.fl_str_mv |
Última atualização do currículo em 14/03/2011 |
dc.contributor.authorID.fl_str_mv |
07cd2bca-7667-4d38-b359-2bb4e1224df8 |
contributor_str_mv |
Fatibello Filho, Orlando |
dc.subject.por.fl_str_mv |
Química analítica Imagens digitais RGB Etanol Sulfito |
topic |
Química analítica Imagens digitais RGB Etanol Sulfito CIENCIAS EXATAS E DA TERRA::QUIMICA |
dc.subject.cnpq.fl_str_mv |
CIENCIAS EXATAS E DA TERRA::QUIMICA |
description |
In this work a simple, fast and inexpensive analytical method was developed to carry out in situ determinations of ethanol and sulfite ions in food samples. The method was based on digital images captured by cameras and / or mobile phones, using a proper device for this purpose. Indirect colorimetry was employed, where it was measured the intensity of the light reflected by the solution, employing the RGB color model. The quantification of the analytes was performed by calibration curve method, using image processing software to obtain the numerical values for each one of the three primary colors (red (R), green (G) and blue (B)). In the first procedure, it was determined the ethanol concentration in drinks, obtaining limits of detection (LOD) and quantification (LOQ) of 0.25 and 0.85 %, respectively, with a linear calibration curve in the range from 1 to 20 % v / v (r = 0.999), using the R channel due to better linearity and results in close agreement to the spectrophotometric method used as reference method, with a confidence level of 95 %. The recovery study was carried out in six commercial samples and the recovery percentage ranged between 85.0 and 106%. The sulfite ions were determined in wines, vinegars and juices samples, with limits of detection (LOD) and quantification (LOQ) of 3.3 × 10-5 mol L -1 and 1.0 × 10 -4 mol L-1, respectively, and with a linear calibration curve from 1.0 × 10-4 to 3.0 × 10-3 mol L1 (r = 0.997) using the B channel supplying a good linearity and results in close agreement to the iodometric titration method employed as reference method, at a confidence level of 95 %. The recovery percentage of sulfite in commercial samples ranged between 84.4 and 103%. |
publishDate |
2013 |
dc.date.available.fl_str_mv |
2013-09-13 2016-06-02T20:36:47Z |
dc.date.issued.fl_str_mv |
2013-07-12 |
dc.date.accessioned.fl_str_mv |
2016-06-02T20:36:47Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.citation.fl_str_mv |
BENEDETTI, Luzia Pires dos Santos. In situ determination of food analytes employing digital images processing by spot tests. 2013. 94 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2013. |
dc.identifier.uri.fl_str_mv |
https://repositorio.ufscar.br/handle/ufscar/6565 |
identifier_str_mv |
BENEDETTI, Luzia Pires dos Santos. In situ determination of food analytes employing digital images processing by spot tests. 2013. 94 f. Dissertação (Mestrado em Ciências Exatas e da Terra) - Universidade Federal de São Carlos, São Carlos, 2013. |
url |
https://repositorio.ufscar.br/handle/ufscar/6565 |
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por |
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por |
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info:eu-repo/semantics/openAccess |
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openAccess |
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Universidade Federal de São Carlos |
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Programa de Pós-Graduação em Química - PPGQ |
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UFSCar |
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BR |
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Universidade Federal de São Carlos |
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