Determination of trace lead in waters by flow injection hydride generation atomic absorption spectrometry

Abstract

Um sistema de injeção em fluxo para determinação de chumbo a concentrações de mg L -1 é proposto usando a Geração de Hidretos e Espectrometria de Absorção Atômica (HG-AAS). Para isto, (NH 4 ) 2 S 2 O 8 a 8,0% (m/v) é usado com agente oxidante e 100 L de amostra e 100 µL de NaBH 4 a 3,0% (m/v) são injetados, simultaneamente, em duas correntes carregadoras de ácido tartárico a 0,5% (m/v) e água desionizada, respectivamente. A freqüência analítica de 150 determinações por hora foi encontrada e o consumo de NaBH 4 de 15 mL e o lixo gerado de 250 mL. O limite de detecção de 0,3 g L -1 para Pb foi obtido e o desvio padrão relativo de 3,0% para 10 g L -1 Pb. O método mostrou-se satisfatório para determinação de traço de Pb em material de referência certificado de águas de consumo e amostras de águas naturais.A flow injection system for lead determination at concentration levels of mg L -1 is proposed using Hydride Generation Atomic Absorption Spectrometry (HG-AAS). To do this, 8.0% (m/v) (NH 4 ) 2 S 2 O 8 is employed as the oxidizing agent, and 100 µL of sample and 100 L of 3.0% (m/v) NaBH 4 are simultaneously injected into two carrier streams, 0.5% (m/v) tartaric acid and de-ionized water, respectively. A sampling rate of about 150 determinations per hour was achieved, requiring 15 mL of NaBH 4 and a waste generation of 250 mL. The detection of limit of 0.3 g L -1 for Pb was achieved and the relative standard deviation of 3.0% for 10 g L -1 Pb was obtained. The method was shown to be satisfactory for determination of traces of Pb in certified reference material of drinking waters and in natural water samples.

Determination of lead in complex sample matrices by atomic fluorescence spectrometry: optimisation of online hydride generation

“…As can be seen in Table 4, the LOD and the linear range of the FeM method were better than other methods exploiting HG-AAS [1,28] and HG-AFS [19]. However, LOD similar or International Journal of Environmental Analytical Chemistry 1063 lower by several orders of magnitude than those of the FeM method were found [17,21].…”

“…RSD was evaluated from 15 successive injections using a Pb standard of 3 µg L −1 for PM and 1.2 µg L −1 for FeM. The detection limit (LOD) was calculated as three times the standard deviation of 10 successive blank signal measurements divided by the slope of the calibration curve (3σ/s), while the quantification limit (LOQ) was calculated as 10σ/s [1]. International Journal of Environmental Analytical Chemistry 1061…”

“…In recent years, interest in the determination of lead has been increased, particularly in biological, food and environmental sample matrices [1][2][3][4]. Lead has been extensively studied due to its high toxicity and bioaccumulation effect in organisms, since it is present in the trophic chain even at very low concentrations [5].…”

Potential Exposure and Risk Associated with Metal Contamination in Foods

“…The generation of Pb hydride was described by Carrijo et al [96]. In this study, a flow injectionhydride generation-atomic absorption spectrometry (FI-HG-AAS) system was used for Pb determination.…”

Separation and preconcentration procedures for the determination of lead using spectrometric techniques: A review

“…Our environment contains countless sources of lead, which is a natural component of soil, water, vegetation, animal life and air [6][7][8][9][10]. In the modern world, it is ubiquitous in food, water and air.…”