Analysis of trace metals Cu2+, Pb2+ and Zn2+ in coastal marine water samples from Florianópolis, Santa Catarina State, Brazil

Abstract

A determinação de metais traço é um indicador importante da toxicidade dessas espécies no ambiente marinho. As técnicas de redissolução são freqüentemente utilizadas, devido a sua sensibilidade e seletividade. Nesta investigação foram determinados parâmetros eletroquímicos para a detecção da concentração dos íons de metais chumbo, zinco e cobre, em águas costeiras, empregando as técnicas de voltametria de redissolução anódica de pulso diferencial (DPASV) e voltametria de redissolução catódica adsortiva de pulso diferencial (DPACSV). Para a determinação do limite de detecção dos íons de metais foram utilizadas amostras sintéticas, em pH 2 para chumbo e zinco e em pH 9 para cobre. Na etapa de validação das metodologias realizada em amostra de água de mar costeira certificada (CASS-4) encontrou-se a concentração de 10,3 nmol L -1 para o íon Cu(II). Utilizou-se o procedimento de enriquecimento e recuperação para os metais analisados sendo obtidos os seguintes percentuais de recuperação:). Os valores de concentrações de metal total foram considerados baixos, quando comparados aos índices estabelecidos pelo CONAMA, principalmente para chumbo e zinco. Para o íon cobre a maior concentração pode ser atribuída ao uso de tintas antiincrustantes e de processos industriais.The determination of trace metal concentrations is an important indicator of toxicity toward species present in ocean environments. Stripping techniques are frequently used, due to their sensitivity and selectivity. In this investigation we were able to determine, efficiently, the concentration of lead(II), zinc(II) and copper(II), in coastal waters, using Differential Pulse Anodic Stripping Voltammetry (DPASV) and Differential Pulse Adsorptive Cathodic Stripping Voltammetry (DPACSV) techniques. For the determination of metal ion detection limits, synthetic samples were used, pH 2 for lead and zinc and pH 9 for copper. In order to check the accuracy of the procedure a certified coastal marine sample (CASS-4) was used and a concentration of 10.3 nmol L -1 for Cu(II) was obtained. The enrichment and recovery method was used for the metals analyzed, the following percent recoveries being obtained: 95±10 (Pb ). The total metal concentrations obtained were considered low, when compared with the indices established by CONAMA, particularly for lead and zinc. For the copper ion the higher concentration may be attributed to its use in the anti-fouling paint, and industrial processes.

Simultaneous determination of zinc, cadmium and lead in environmental water samples by potentiometric stripping analysis (PSA) using multiwalled carbon nanotube electrode

“…Despite the efforts of the scientific community to develop alternative forms to reduce the disposal of metal ions in water bodies, including different treatment effluents such as precipitation, membrane filtration, ion exchange and adsorption [1], the levels of toxic metals disposed into water bodies are still rising, mainly in aqueous effluents discharged into lake waters [2]. Owing to their potential danger to aquatic life, especially at high levels, there is a growing need for simultaneous monitoring of metal ions, such as zinc, cadmium and lead in different kind of water samples.…”

Química no Brasil: perspectivas e necessidades para a próxima década - Documento básico

“…Domínios como nanociência e nanotecnologia [11][12][13] , fármacos [14][15][16][17][18] , ambiente [19][20][21][22][23][24][25][26] …”

Evaluation of Histidine Functionalized Multiwalled Carbon Nanotubes for Improvement in the Sensitivity of Cadmium Ions Determination in Flow Analysis

“…Some efforts have been carried out to develop many treatment processes to reduce the disposal of heavy metal ions mainly in water bodies. The different treatment processes include precipitation, membrane filtration, ion exchange and adsorption (Tokalıoğlu et al 2009), however, the levels of heavy metals disposal into water bodies are still rising, mainly in aqueous effluents discharged into aquatic bodies (Mello et al 2005). As example, lead is considered as the major environmental pollutant and has become the most widely scattered toxic heavy metal in the world as a result of anthropogenic action.…”