Mesoporous titanium dioxide as a novel solid-phase extraction material for flow injection micro-column preconcentration on-line coupled with ICP-OES determination of trace metals in environmental samples
ABSTRACT Mesoporous titanium dioxide as a novel solid-phase extraction material for flow injection micro-column preconcentration on-line coupled with ICP-OES determination of trace metals (Co, Cd, Cr, Cu, Mn, Ni, V, Ce, Dy, Eu, La and Yb) in environmental samples was described. Possessing a high adsorption capacity towards the metal ions, mesoporous titanium dioxide has found to be of great potential as an adsorbent for the preconcentration of trace metal ions in samples with complicated matrix. The experimental parameters including pH, sample flow rate, volume, elution and interfering ions on the recovery of the target analytes were investigated, and the optimal experimental conditions were established. Under the optimized operating conditions, a preconcentration time of 90s and elution time of 18s with enrichment factor of 10 and sampling frequency of 20h(-1) were obtained. The detection limits of this method for the target elements were between 0.03 and 0.36mugL(-1), and the relative standard deviations (R.S.D.s) were found to be less than 6.0% (n=7, c=5ngmL(-1)). The proposed method was validated using a certified reference material, and has been successfully applied for the determination of the afore mentioned trace metals in natural water samples and coal fly ash with satisfactory results.
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ABSTRACT: Cadion was coated on carbon powder and used as a solid phase for selective extraction and preconcentration of cadmium ions. Complexed cadmium ions were eluted from solid phase by 5 mL, nitric acid (2.0 M) with the flow rate of 2 mL min(-1).The resulted solution was used for accumulation of the cadmium metal at the surface of the carbon paste electrode at -1.3 V reduction potential. Finally, cadmium was reoxidized and the differential pulse voltammogram recorded at the potential range of -0.55 to -0.2 V. Calibration graph was plotted in the concentration range of 0.5-50 μg L(-1) of cadmium. Detection limit 0.06 μg L(-1) was calculated based on the 3 Sb/m. The RSD was 9.13 % (n = 4) for cadmium concentration of 10 μg L(-1) with preconcentration factor of 100. Method was successfully used for the determination of cadmium in finger nail samples and after spiking the samples, the recoveries were evaluated >96 %.Bulletin of Environmental Contamination and Toxicology 02/2015; 94(4). DOI:10.1007/s00128-015-1484-x · 1.22 Impact Factor
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ABSTRACT: Nano-alumina modified by 9-aminoacridine was used as a sorbent for separation and determination of dichromate ions from water. Statistical method, based on surface response design, has been used for the optimization of dichromate ions elution from 9-aminoacridine nano-alumina. The adsorbed dichromate ions were found to be eluted quantitatively with 0.8 mol L À1 KCl in 1.6 mol L À1 NaOH which optimized by response surface design. Under optimum conditions, the accuracy, precision (relative standard deviation, RSD%) and R-square of the method were calculated as >98, <3, and >94%, respectively. Remarkable agreement between experimental and theoretical data was confirmed the predicted assumption. The method was applied to the simultaneous determination of dichromate in natural and industrial water samples. We also examined the retention of dichromate anions in the presence of Cl À , NO À 3 , and SO 2À 4 anions at pH 3.CLEAN - Soil Air Water 03/2012; 40(3):272-277. DOI:10.1002/clen.201000224 · 1.84 Impact Factor
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ABSTRACT: Peanut shell was chemically modified with phosphoric acid and used as a solid phase extraction material for the determination of trace amounts of Pb2+ and Cd2+ in food samples by flame atomic absorption spectrometry. The effect of pH, sample flow rate and volume, elution flow rate and volume, and of potentially interfering ions on the recovery of the analytes were investigated. The results showed that Pb2+ and Cd2+ can be adsorbed at pH6 and eluted with 1.5mL of 0.1mol L−1 HCl. Under the optimized conditions, the adsorption capacity of modified peanut shell was found to be 116.7mg g−1 and 37.5mg g−1 for Pb2+ and Cd2+, respectively. The limits of detection were as low as 2.3 and 0.2ngmL−1 for Pb2+ and Cd2+, respectively, with a theoretical concentration factor of 40. The analytical results for the certified reference tea sample (GBW07605) were in a good agreement with the certified value. The method has also been applied to the determination of trace Pb2+ and Cd2+ in tea, liquor and milk powder, and the recovery of Pb2+ and Cd2+ for spiked food samples was between 90 and 114%.Microchimica Acta 04/2009; 165(1):237-242. DOI:10.1007/s00604-008-0126-y · 3.72 Impact Factor