Simultaneous monitoring of toxic metals on white poplar (populus) by SWASV

Abstract

foi utilizada na determinação simultânea de quantidades traço dos metais tóxicos Pb(II), Cd(II) e Cu(II) em folhas de choupo (populus), utilizadas como bio-indicador, recolhidas numa área de tráfego automóvel intenso da cidade de Lisboa. As folhas, após secagem, foram submetidas a um processo de digestão ácida por microondas. Para a aplicação desta técnica à análise das folhas foi realizado um estudo de optimização dos vários parâmetros voltamétricos. O eletrodo de trabalho consistiu num filme de mercúrio depositado numa superfície de carbono vítreo. O sistema Ag/AgCl foi utilizado como referência e um fio de Platina como eletrodo auxiliar. Concentrações médias (em mg de metal/kg de matéria seca -folhas) de 2,6, 0,18 e 5,0 foram obtidas para o Pb(II), o Cd(II) e o Cu(II), respectivamente. O valor obtido para o chumbo coincide com o obtido pelo método de referência baseado na Espectrofotometria de Absorção Atômica em Forno de Grafite (EAAFG).Square wave anodic stripping voltammetry (SWASV) was applied to the simultaneous determination of trace amounts of toxic metals Pb(II), Cd(II) and Cu(II) in white poplar (populus) leaves, used as bio indicator and gathered in a chosen area of the city of Lisbon with very high traffic intensity. The leaves were dried and subsequently exposed to an acid digestion microwave process. Square wave parameters were optimized for the voltammetric analysis of the samples. The working electrode consisted of a thin mercury film (TMFE) deposited on the surface of vitreous carbon. The pair Ag/AgCl was used as the reference electrode and a Pt wire as the auxiliary electrode. Average concentrations (in mg of metal/kg of dry matter-leaves) of 2.6, 0.18, and 5.0 were obtained for Pb(II), Cd(II) and Cu(II), respectively. The value for lead coincides with the one obtained by the reference method based on Graphite Furnace Atomic Absorption Spectrophotometry (GFAAS).

Metal Characterization of White Hawthorn Organs and Infusions

“…25 These values are similar to those determined in the present study, namely, 1.5−2 μg/g, 0.12− 0.14 μg/g, and 6−7.5 μg/g for Pb, Cd, and Cu, respectively. Peppermint leaves, however, were found to contain 2.41 μg/g Pb, 0.09 μg/g Cd, and 12 μg/g Cu.…”

“…Leaves of poplar analyzed in Portugal were found to have the following concentrations: 2−3 μg/g for Pb, 0.1−0.2 μg/g for Cd, and 4−5 μg/g for Cu. 25 These values are similar to those determined in the present study, namely, 1.5−2 μg/g, 0.12− 0.14 μg/g, and 6−7.5 μg/g for Pb, Cd, and Cu, respectively. Peppermint leaves, however, were found to contain 2.41 μg/g Pb, 0.09 μg/g Cd, and 12 μg/g Cu.…”

Determination of selected toxic elements in leaves of White Hawthorn grown in a remote area

“…A study of poplar leaves (Portugal) obtained values of 2 to 3 µg/g for Pb, 0.1 to 0.2 µg/g for Cd, and 4 to 5 µg/g for Cu (Silva et al 2005). These results are in the same order of magnitude as those of the presented study, namely 1.5 to 2 µg/g, 0.12 to 0.14 µg/g, and 6 to 7.5 µg/g for Pb, Cd, and Cu, respectively.…”

Use of Black Poplar Leaves for the Biomonitoring of Air Pollution in an Urban Agglomeration

“…Numerous studies reported the poplar’s efficiency in phytoremediation and the effect of metals on the poplar’s physiological processes. Regarding the poplar’s biomonitoring capabilities, most of the research focuses on their use in soil pollution and only a few in air pollution [ 16 , 17 , 22 , 23 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ].…”