Flotation Separation and Flame Atomic Absorption Spectrometric Determination of Trace Amount of Lead in Some Environmental Samples

Abstract

A flotation method based on formation of an ion-associate complex between ferroin and Pb(II)-thiosulfate complex is proposed for the quantitative separation and preconcentration of Pb(II) content in various environmental samples. The flotation process was carried out using a 250-mL aliquot of the aqueous solution at the buffering pH of 8.50 in which the ion-associate complex was floated at the interface of the aqueous/xylene phases. The ion-associate complex was then dissolved in 5 mL of acidic solution of 0.05 M KClO 3 and the Pb(II) content was determined by flame atomic absorption spectrometry (FAAS). By this method, a preconcentration factor of 50 can be achieved so that the determination of trace amounts of Pb(II) ions is feasible in the range of 1×10 -7 to 1.2×10 -6 M. The LOD and RSD (n=7) were obtained as 1.5×10 -8 M and 1.5%, respectively. It was found that a large number of cations and anions even at high considerably foreign ion/Pb(II) ratios were not interfered. In treatment with a SRM water sample and a synthetic liquid extract of vegetable, the recoveries were more than 95%s, which confirmed validity of the method. The method was satisfactorily applied for determining of trace amount of Pb(II) in some complex matrices.

Gadolinium hydroxide coprecipitation system for the separation–preconcentration of some heavy metals

“…The detection limits of analyte ions investigated are superior to those of preconcentration techniques for analyses [26][27][28][29][30][31][32][33][34]. The good features of the proposed coprecipitation method showed that it is a convenient and simple one.…”

A solid phase extraction procedure for Fe3+, Cu2+ and Zn2+ ions on 2-phenyl-1H-benzo[d] imidazole loaded on Triton X-100-coated polyvinyl chloride

“…Preconcentration can solve the above two problems and leads to simplified heavy metal determination [9][10][11][12][13][14]. Solid phase extraction is a universal technique in this respect compared to the conventional liquid extraction [15][16][17][18]. Solid phase extraction is based on the utilization of a major constituent as bonded stationary phase immobilized with different ligand or functional group.…”

“…Solid phase extraction is based on the utilization of a major constituent as bonded stationary phase immobilized with different ligand or functional group. The nature of the functional group determines the phase selectivity for metal ion while the regeneration of the phase depends on polymer matrix [15][16][17][18][19].…”

5-Chloro-2-hydroxyaniline–copper(II) coprecipitation system for preconcentration and separation of lead(II) and chromium(III) at trace levels

“…The use of a separation-preconcentration step prior to heavy metal determination is usually necessary since the presence of heavy metals in environmental samples is at low levels. Methods including cloud point extraction, membrane filtration, solvent extraction, solid phase extraction, ion-exchange, solvent sublation, and electroanalytical techniques are widely used to solve these problems [20][21][22][23][24][25][26][27].…”