Sodium dodecyl sulfate coated γ-alumina support modified by a new Schiff base for solid phase extraction and flame-AAS determination of lead and copper ions

Abstract

Recebido em 21/3/13; aceito em 16/5/13; publicado na web em 25/7/13 A simple and fast approach for solid phase extraction is herein described, and used to determine trace amounts of Pb 2+ and Cu 2+ metal ions. The solid phase support is sodium dodecyl sulfate (SDS)-coated γ-alumina modified with bis(2-hydroxy acetophenone)-1,6-hexanediimine (BHAH) ligand. The adsorbed ions were stripped from the solid phase by 6 mL of 4 M nitric acid as eluent. The eluting solution was analyzed by flame atomic absorption spectrometry (FAAS). The sorption recovery of metal ions was investigated with regard to the effects of pH, amount of ligand, γ-alumina and surfactant and the amount and type of eluent. Complexation of BHAH with Pb 2+ or Cu 2+ ions was examined via spectrophotometry using the HypSpec program. The detection limit for Cu 2+ was 7.9 µg L -1 with a relative standard deviation of 1.67%, while that for Pb 2+ was 6.4 µg L -1 with a relative standard deviation of 1.64%. A preconcentration factor of 100 was achieved for these ions. The method was successfully applied to determine analyte concentrations in samples of liver, parsley, cabbage, and water.

Formation of a Eu(iii) borate solid species from a weak Eu(iii) borate complex in aqueous solution

“…18 The application of HypSpec has been demonstrated in several studies. [19][20][21][22] The data set for the fitting procedure contained as parameters the model, total metal and ligand concentrations, pH, protonation constant of the ligand, the measured europium luminescence spectra and the Eu(III) aquo ion luminescence spectrum as the known spectrum, respectively. Simplifications and approximations for the calculation of this complexation system are described in the section "Results and discussion".…”

Solution scanometry, a new method for determination of acidity constants of indicators

“…[29][30][31][32][33][34] HypSpec is a new program for calculation of the pK a of ligands 35,36 and stability constants of complexes in aqueous and nonaqueous solutions, using spectrophotometric data. [37][38][39] The solution scanometric technique was introduced recently by Abbaspour et al 40 The method is based on scanning of Plexiglas® cells containing colored solutions. The Plexiglas® cells were scanned and nally the RGB (red, green and blue) color model was used in color monitoring.…”

The interaction of Eu(iii) with organoborates – a further approach to understand the complexation in the An/Ln(iii)–borate system

“…35 Applications of this software can be found in various studies. [36][37][38][39] Our determined values of pK a , lg K BL and lg β were extrapolated to infinite dilution, following the extended Debye-Hückel approach as published by Davies, 1962. 40 Throughout the paper all given uncertainties correspond to 2σ, i.e., the 95% confidence level.…”