Preconcentration of Gallium by Coprecipitation with Synthetic Zeolites Prior to Determination by Electrothermal Atomic Absorption Spectrometry

Abstract

Electrothermal atomic absorption spectrometry (ETAAS) has been widely used for trace metal ions analysis. The variable preconcentration methods, such as flotation, solvent extraction, solid phase extraction (SFE) and ion exchange, were generally associated with ETAAS in order to improve the detection limit and separate the target metal ions from the matrix.Coprecipitation is one of the more effective preconcentration method for trace metal ions in water samples, and several coprecipitants, such as hydroxides of indium, 1 hafnium, 2,3 iron, nickel-8-quinolinol/1-nitroso-2-naphthol, 16 and chitosan, 17 have been reported. Similarly, SFE is also an effective preconcentration method, and several adsorbents, such as ion-exchange resin, chelating resin and activated carbon, have been used. Synthetic zeolites are extensively used in adsorption, ion-exchange and separation processes, due to their unique structural properties. Moreover, synthetic zeolites have been employed as useful catalysts and detergent builders and for purification processes, such as air decontamination and gas sweetening. On the other hand, synthetic zeolites are dissolved in some acids, such as nitric acid, hydrochloric acid and sulfuric acid, because the synthetic zeolite structure is composed of aluminum oxide and silicon oxide. Nevertheless, concerning synthetic zeolites as useful materials, there have been few reports for on application of synthetic zeolites as preconcentrating trace metal ions. 18When an acid solution containing dissolved synthetic zeolite was added to water samples containing trace metal ions and the pH of the sample solution was neutralized, alumino-silicate amorphous precipitates were formed and metal ions were concentrated from the sample solution into these precipitates.Although gallium is important for use in the semiconductor industry, gallium particles and gallium compounds, such as gallium arsenide, have been identified as potential health hazards. Therefore, from an environmental standpoint, the need for sensitive and reliable methods for determining trace concentrations of gallium has become apparent in various fields. ETAAS is an effective analytical method for the determination of trace amounts of gallium. Further, solvent extraction, 19 adsorption, 20 ion exchange, 21 membrane, 22 and coprecipitation, 23 have been used to preconcentrate gallium prior to ETAAS analysis in order to improve the detection limit. However, there have been no reports on the use of a synthetic zeolite as a coprecipitant for gallium. This paper describes the fundamental conditions for the coprecipitation of gallium using a synthetic zeolite and for the ETAAS analysis of trace gallium in water samples. Higashikasai, Edogawa, Japan Synthetic zeolites were dissolved in nitric acid, and the resulting solution used as a coprecipitant for the preconcentration of trace amounts of gallium in water samples prior to determination by electrothermal atomic absorption spectrometry (ETAAS). The gallium preconcentration conditions and the ETAAS m...

Enrichment/separation of cadmium(II) and lead(II) in environmental samples by solid phase extraction

“…Also lower elements concentrations than the detection limits of the instrumental technique are another problem in the trace heavy metal determinations in environmental samples. Consequently, a preconcentration/separation process is usually required [6][7][8][9][10]. Coprecipitation [11][12][13], membrane filtration [14,15], electrodeposition [16], cloud point extraction [17] and solvent extraction [18][19][20][21] are the popular methods for the preconcentration and separation of the traces transition metal ions.…”

Solid Phase Extraction and Preconcentration of Trace Gallium, Indium, and Thallium Using New Modified Amino Silica

“…Various procedures have been used for this aim including liquid-liquid extraction, 21,22 co-precipitation, 23 ion exchange, 24 cloud point extraction (CPE) 7,16 and solid phase extraction (SPE). 8,9 The latter is preferable due to its simplicity, higher enrichment factors, low cost and lower consumption of toxic chemicals.…”

Extraction of Trace Cd(II) in Real Samples using Multi Walled Carbon Nanotubes Carboxylate

“…Also lower elements concentrations than the detection limits of the instrumental technique are another problem in the trace heavy metal determinations in environmental samples. Consequently, a preconcentration/ separation process is usually required [6][7][8][9][10] . Coprecipitation [11][12][13] , membrane filtration 14,15 , electrodeposition 16 , cloud point extraction 17 and solvent extraction [18][19][20][21] are the popular methods for the preconcentration and separation of the traces transition metal ions.…”