Salicylic acid functionalized silica-coated magnetite nanoparticles for solid phase extraction and preconcentration of some heavy metal ions from various real samples

A method for the preconcentration of trace heavy metal ions in environmental samples has been reported. The presented method is based on the sorption of Cu(II), Cd(II), Ni(II) and Cr(III) ions with salicylic acid as respective chelate on silica-coated magnetite nanoparticles. Prepared adsorbent was characterized by XRD, SEM, BET and FT-IR measurements. The metals content of the sorbed complexes are eluted using 4.0 mL of 1.0 mol L-1 nitric acid. The influences of the analytical parameters including pH, amount of solid phase and condition of eluting solution, the effects of matrix ions on the retention of the analytes were examined. The accuracy and precision of suggested method were tested by analyzing of certified reference materials. The detection limits (3Sb/m, N = 8) for Cu(II), Cd(II), Ni(II) and Cr(III) ions are 0.22, 0.11, 0.27 and 0.15 μg L-1, respectively, and the maximum preconcentration factor is 200. The method was successfully applied to the evaluation of these trace and toxic metals in various waters, foods and other samples

Determination of some trace metals in water and sediment samples by flame atomic absorption spectrometry after coprecipitation with cerium (IV) hydroxide

A cerium(IV) hydroxide coprecipitation method was developed for the determination of some trace elements (Cu, Co, Pb, Cd, Ni) in aqueous solutions, water and sediment samples by flame atomic absorption spectrometry (AAS). Several parameters governing the efficiency of the coprecipitation method were evaluated including pH of sample solution, amount of carrier element, volume of sample solution and the effect of possible matrix ions The procedure was validated by the analysis of GBW 07309 standard reference material sediment and by use of a method based on a solid phase extraction. © 2002 Elsevier Science B.V. All rights reserved

Determination of total chromium by flame atomic absorption spectrometry after coprecipitation by cerium (IV) hydroxide.

A method for the preconcentration of the total chromium based on coprecipitation with cerium (IV) hydroxide is proposed for determination of chromium by flame atomic absorption spectrometry. Different factors including carrier element amount, pH, sample volume and matrix ion effects for the precipitation were examined. The detection limit of the total chromium (k=3, N=15) was 0.18 microg l(-1). The presented method was applied for the determination of chromium in the wastewater samples from Kayseri and Nigde Organized Industrial Region-Turkey and in drinking water from our laboratory, Kayseri with satisfactory results (relative standard deviations below 8%, recoveries 95%). The analytical results obtained by the proposed method for certified copper sample was in good agreement with the certified value

DETERMINATION OF TRIAZINE HERBICIDES AND METABOLITES BY SOLID PHASE

An efficient solid phase extractive preconcentration/separation method was developed for the trace determination of herbicides in aqueous samples using Amberlite XAD-4 resin as the adsorbent. The retained herbicides were eluted with methanol at a flow rate of 1.0mLmin(-1) and determined by HPLC-DAD (wavelength of 220nm) using water (pH:4.7, phosphoric acid) and methanol (ratio 35:65) as the mobile phase with a flow rate of 1.0mLmin(-1). Quantitative recoveries of simazine, atrazine and its metabolities were achieved at optimized analysis conditions that included 0.75g of resin; a pH of 3.0; an eluent volume of 3.0mL; an eluent flow rate of 1.0mLmin(-1); and a sample flow rate of 4.0mLmin(-1). The limits of detection, preconcentration factor, and linear ranges for the herbicides were 0.084-0.121 mu gL(-1), 1000, and 0.5-20mgL(-1), respectively. The performance of the method was evaluated by analysis of spiked water samples. The recoveries of simazine, atrazine and their metabolities were found to be quantitative (99.6-104.8%) with RSDs of 2.2-4.8% and 2.8-4.7% for intra-day and inter-day precision, respectively. The proposed method was successfully applied for trace determination of studied analytes in waste water, apple juice, and red wine samples

adsorption resin

A rapid, sensitive, and facile method for enrichment and separation of trace amounts of gallium was established by using mini column filled Amberlite XAD-4. Gallium(III) as a 4-(2-thiazolylazo) resorcinol (TAR) complex is sorbed on the Amberlite XAD-4 resin and is easily eluted by using 1 M nitric acid in acetone. The determinations of gallium were performed by atomic absorption spectrometry. The influences of the analytical parameters including amounts of reagents, pH of the solutions, and type of eluent were also investigated. The influences of several ions, as interferents, were discussed. The accuracy of the method was demonstrated by recovery on spiked samples. The presented procedure was applied to the determination of gallium in reference standard sediment material (GBW 07309) and water samples with satisfactory results (recovery 95%; relative error 3%; relative standard deviation 10%)

Determination of cobalt, nickel and iron at trace level in natural water samples by in-column chelation-reversed phase high-performance liquid chromatography.

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) 0.9991). 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

New use of polypyrrole-chloride for selective preconcentration of copper prior to its determination of flame atomic absorption spectrometry.

Polypyrrole-chloride was studied as a new sorbent for preconcentration of copper(II) using solid-phase extraction prior to determination by flame atomic absorption spectrometry. The sorbent showed an extremely high selectivity towards copper(II) as an anionic chelate, i.e. Cu (pyrocatechol violet)(2)(2-) in the pH range of 4-7. Copper(II) as Cu (pyrocatechol violet)(2)(2-) was selectively retained on a column containing 1.0 g of polypyrrole-chloride and quantitatively eluted by 3 mL of 2.0 mol L(-1) nitric acid. The calibration graph was linear with a correlation coefficient of 0.999 at levels near the detection limit and up to at least 50 microg L(-1). When applied for preconcentration and determination of copper in tap water, waste water and hot spring water, the recoveries were found to be 96, 101 and 95%, respectively, with high precision (% relative standard deviation <4%) and low detection limit (0.87 microg L(-1)). Verification of the accuracy was carried out by the analysis of a standard reference material (BCR 715 wastewater-SRM). The relative error was +3.33%. The proposed method was successfully applied to the determination of copper in tap water, waste water and hot spring water samples

in urine after enrichment on cellulose nitrate membrane filter system

Atomic absorption spectrometric determination of chromium, iron and lead in urine were performed in the present work, after separation and preconcentration procedure including calmagite chelates of the analyte ions on cellulose nitrate membrane filter. The effects of major components of urine including urea, creatine on the quantitative recoveries of Cr, Fe and Ph were discussed. The procedure presented was successfully applied for the determination of these ions in urine samples (recoveries > 95%, relative standard deviations below 10%)

chromatography

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) 0.9991). 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