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ABSTRACT: Simple, robust and novel analytical procedures were developed for the speciation of chromium by carrier element co-precipitation (CECP) and dispersive liquid–liquid microextraction (DLLME) coupled with microsample injection system–flame atomic absorption spectrophotometry (MIS–FAAS). Ammonium pyrrolidine dithiocarbamate (APDC), carbon tetrachloride and ethanol were used as chelating agent, extraction solvent and disperser solvent, respectively for the determination of Cr(VI) by DLLME. For total chromium, Cr(III) was oxidized by Ce(SO4)2 in acidic media (0.07 mol L−1 H2SO4) and the resulting solution was co-precipitated with APDC. The concentration of Cr(III) was estimated by determining the difference between the concentration of total chromium and that of Cr(VI). The maximum recovery of Cr(VI) was obtained with DLLME at optimal conditions of pH 3.0 , 0.25% APDC, 100 μL CCl4, 1.00 mL of CH3CH2OH and 0.01 mg L−1 Cr(VI). Whereas, the optimal conditions for CECP were 40 mL initial volume of water samples, 0.25% APDC, 0.02% Ce(SO4)2 and 0.10 mg L−1 Cr(VI) concentration. The limits of detection and enrichment factor of DLLME and CECP were [0.037 and 2.13] and [400 and 100] μg L−1, respectively with 40 mL initial volumes. The relative standard deviations (RSD, n = 6) were <4%. The proposed method was successfully applied to the chromium speciation at ultra-trace levels in natural drinking water, industrial effluents waste water and an exchangeable fraction of garden soil from Denizli. Moreover, the proposed methods compared well with the literature reported method.
Journal of Analytical Atomic Spectrometry 01/2012; · 3.22 Impact Factor
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ABSTRACT: This paper reports the utilization of 4-(2-pyridylazo) resorcinol (PAR) as a chelating reagent for in-column derivatization and the determination of trace Co, Fe, and Ni ions by reversed-phase high-performance liquid chromatography with photodiode array detector. A good separation of Co, Fe, and Ni chelates were achieved by using an Inertsil ODS-3 column and a mobile phase, consisted of methanol-THF-water mixture (50:5:45) containing ammonium acetate buffer (pH 5.0) and PAR. After full optimization, good repeatability of retention times (relative standard deviation (RSD) < 0.05%) and peak areas (RSD < 1.7%) was achieved as well as a good linearity (r (2) > 0.9991). The detection limits (S/N = 3), expressed as micrograms per liter, were 0.50 (Co), 9.07 (Fe), and 2.00 (Ni). The applicability and the accuracy of the developed method were estimated by the analysis of spiked water samples and certified reference material BCR 715 wastewater-SRM.
Environmental Monitoring and Assessment 06/2011; 184(6):3469-79. · 1.40 Impact Factor
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ABSTRACT: Speciation of chromium in some plant leaves, soil and sediment samples was carried out by selective leaching of Cr(VI) using a sodium carbonate leaching procedure. Total chromium from the samples was extracted using aqua regia and oxidative acid digestion, respectively. The concentrations of chromium species in the extracts were determined using by graphite furnace atomic absorption spectrometry (GFAAS). Uncoated graphite furnace tubes were used as an atomizer. Due to the presence of relatively high amounts of Na(2)CO(3) in the resulting samples, the possible influences of Na(2)CO(3) on the absorbance signals were checked. There is no interference of Na(2)CO(3) on the chromium absorbance up to 0.1 mol L(-1) Na(2)CO(3). A limit of detection (LOD) for determination of Cr(VI) in 0.1 Na(2)CO(3) solution by GFAAS was found to be 0.93 microg L(-1). The procedure was applied to environmental samples. The relative standard deviation, R.S.D. as precision for 10 replicate measurements of 20 microL(-1) Cr in processed soil sample was 4.2%.
Journal of hazardous materials 09/2009; 173(1-3):778-82. · 4.14 Impact Factor
