Lead determination using hydride-atomic absorption

In the case of moss samples exposed in the Mansfelder Land area, inductively coupled plasma atomic emission spectrometry (ICP-AES) was used for the determination of As, Cu, Fe, Mn, Ni, Pb, Zn in both aqueous and acidic solutions by standard addition technique. Atomic absorption techniques were applied for the determination of arsenic (hydride generation coupled with graphite furnace atomization), cadmium and lead (both by Zeeman-corrected graphite furnace AAS) (Krauss et al., 1998, 2000). Ion chromatography was used for the determination of sulphate. 

Fiydride generation (and cold-vapor) techniques significantly improve atomic absorption spectrometry (AAS) concentration detection limits while offering several advantages (1) separation of the analyte from the matrix is achieved which invariably leads to improved accuracy of determination (2) preconcentration is easily implemented (3) simple chemical speciation may be discerned in many cases and (4) the procedures are amenable to automation. Disadvantages with the approach that are frequently cited include interferences from concomitant elements (notably transition metals), pH effects, oxidation state influences (which may be advantageously used for speciation) and gas-phase atomization interferences (mutual effect from other hydrides). 

Quartz tube (QT) atomisation and high-resolution continuum source hydride generation atomic absorption spectrometry (FIR-CS HG-AAS) were used to determine lead. A full two-level factorial design characterised the effects of the reagent concentrations. The experimental conditions were determined using a Box-Behnken design. 

S. L. C. Ferreira, D. C. Lima, I. T. A. Moreira and O. M. C. de Oliveira, Critical study using experimental design of the determination of lead by high-resolution continuum source hydride generation atomic absorption spectrometry, J. Anal. At. Spectrom., 2011, 26(10), 2039-2044. 

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