Wavelet-Based determination of Cu and Pb in water samples using potentiometric stripping analysis with a Lab-Made potentiostat

Abstract

Este artigo demonstra a possibilidade de se realizar uma determinação simultânea de chumbo e cobre em água mineral, de rio e de torneira mediante análise por redissolução potenciométrica empregando um potenciostato lab-made de baixo custo e um método de processamento de sinais baseado em wavelets. As concentrações encontradas para Pb(II) e Cu(II) situaram-se na faixa 3-7 µg L -1. Os desvios padrão relativos foram em média menores que 3%, o que é satisfatório tendo em vista as baixas concentrações dos analitos. Para comparação, a determinação foi também realizada empregando um equipamento comercial de alto padrão (µAutolab Type II, Eco Chemie).As médias e desvios padrão dos resultados foram similares aos obtidos com o potenciostato labmade. Não foi verificada diferença estatística significativa de acordo com um teste t pareado ao nível de confiança de 95%. This paper demonstrates the possibility of simultaneously determining lead and copper in mineral, river and tap water by potentiometric stripping analysis using a low-cost lab-made potentiostat and a wavelet-based signal processing method. Pb(II) and Cu(II) concentrations were found to be in the range 3-7 µg L -1. Relative standard deviations were on average smaller than 3%, which is satisfactory in view of the trace concentration. For comparison, the determination was also carried out by using a high-end commercial equipment (µAutolab Type II, Eco Chemie). The average and standard deviation of the results were similar to those obtained with the labmade potentiostat. No significant statistical difference was verified according to a paired t-test at a confidence level of 95%.

Analytical chemistry in Brazil: healthy and growing

“…283 Results obtained with a lab-made low-cost potentiostat agreed with those attained using commercial equipment, with coefficient of variation lower than 3%.…”

Cadmium and lead levels consumed by patients with oral hospital diets prescriptions

“…In the case of Pb, any additional amount ingested via potable water would increase the exposition to the element to the point of configuring a lack of food safety. In Brazil a study showed that the lead content of water varied between 3.9 and 5.3 µg/L for mineral water, and was 4.7 µg/L for potable tap water 20 . Considering a maximum consumption of 2L of mineral water per day per patient, the contribution to the daily lead consumption would be to the order of 7.8 to 10.6 µg in the months of september 2010 and january 2011, respectively.…”