A Low-Cost Video-Based Reflectometer for Selective Detection of Cu2+ Using Paper-Based Colorimetric Sensors

• Autor(a) principal: Morais,Camilo L. M.
• Data de Publicação: 2017
• Outros Autores: Silva,Lilian C. da, Pinheiro,Nayara A., Menezes,Fabrício G., Lima,Kássio M. G.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Journal of the Brazilian Chemical Society (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-50532017001202506
• topic: reflectometer; webcam; paper-based colorimetric sensor; low-cost instrumentation; Cu2+

This paper presents a low-cost reflectometer for selective detection of Cu2+. The reflectometer is based on an emission light source using five light-emitting diodes at different wavelengths and a detector using a webcam. The samples were prepared using a filter paper-based colorimetric sensor with ascorbic acid-based quinoxaline derivative. Video analysis using gray color intensity was used to perform both copper ion screening (Cu2+, Pb2+, Cr+3, Ni2+, Fe2+, Sn2+, Mg2+, Cd2+, Ag+ and Co2+) and quantification of Cu2+ in spiked samples. In addition, a multivariate validation was performed. The system proved to be selective to Cu2+ among the screened ions, and its quantification was performed using partial least square regressions. Good linearity (R2 = 0.979, coefficient of determination), low root-mean-square error of prediction (RMSEP = 5.20 × 10-3 mol L-1) and high recovery (93.39-128.64%) were achieved. This method has potential to be employed for rapid and selective determination of Cu2+ in water using low-cost instrumentation.