Desenvolvimento de um fotômetro LED-Vis portátil e microcontrolado por Arduino
Ano de defesa: | 2014 |
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Autor(a) principal: | |
Orientador(a): | |
Banca de defesa: | |
Tipo de documento: | Dissertação |
Tipo de acesso: | Acesso aberto |
Idioma: | por |
Instituição de defesa: |
Universidade Federal da Paraíba
BR Química Programa de Pós-Graduação em Química UFPB |
Programa de Pós-Graduação: |
Não Informado pela instituição
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Departamento: |
Não Informado pela instituição
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País: |
Não Informado pela instituição
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Palavras-chave em Português: | |
Link de acesso: | https://repositorio.ufpb.br/jspui/handle/tede/7136 |
Resumo: | A portable and low-cost photometer is proposed in this work. The instrument uses a tri-color light emitting diode (LED) as its radiation source in maximum emission wavelengths of 480 (blue), 534 (green) and 630 nm (red). It employs a phototransistor with spectral sensitivity in the visible region, as well as an Arduino microcontroller. Its analytical performance was evaluated by means of quantitative analysis (analytical curves), whose models were validated by analysis of variance (ANOVA). The instrument was applied to determine sunset yellow dye in energy drinks and sodas, and potassium permanganate pills. For comparison purposes, a commercial spectrophotometer was used to construct the calibration curves for the reference method. Applying the paired t-test at a 95 % confidence level for the concentration results obtained with the two instruments, we observed no statistically significant difference. Furthermore, accurate concentration estimates were obtained for the analytes as confirmed by the low relative standard deviation range of 0.2 and 0.5%, respectively, for both the dye and the permanganate. The proposed photometer might be an economically viable alternative to spectroscopic analysis, especially in teaching laboratories with limited financial resources or lacking in highly qualified personnel. |