Erdal Kendüzler

Separation and preconcentration of trace manganese from various samples with Amberlyst 36 column and determination by flame atomic absorption spectrometry

This work assesses the potential of a new adsorptive material, Amberlyst 36, for the separation and preconcentration of trace manganese(II) from various media. It is based on the sorption of manganese(II) ions onto a column filled with Amberlyst 36 cation exchange resin, followed by the elution with 5mL of 3mol/L nitric acid and determination by flame atomic absorption spectrometry (FAAS) without interference of the matrix. Different factors including pH of sample solution, sample volume, amount of resin, flow rate of sample solution, volume and concentration of eluent, and matrix effects for preconcentration were investigated. Good relative standard deviation (3%) and high recovery (>95%) at 100mug/L and high enrichment factor (200) and low analytical detection limit (0.245mug/L) were obtained. The adsorption equilibrium was described well by the Langmuir isotherm model with maximum adsorption capacity of 88mg/g of manganese on the resin. The method was applied for the manganese determination by FAAS in tap water, commercial natural drinking water, commercial treated drinking water and commercial tea bag sample. The accuracy of the method is confirmed by analyzing the certified reference material (tea leaves GBW 07605). The results demonstrated good agreement with the certified values.

Determination and interference studies of bismuth by tungsten trap hydride generation atomic absorption spectrometry

The determination of bismuth requires sufficiently sensitive procedures for detection at the microg L(-1) level or lower. W-coil was used for on-line trapping of volatile bismuth species using HGAAS (hydride generation atomic absorption spectrometry); atom trapping using a W-coil consists of three steps. Initially BiH(3) gas is formed by hydride generation procedure. The analyte species in vapor form are transported through the W-coil trap held at 289 degrees C where trapping takes place. Following the preconcentration step, the W-coil is heated to 1348 degrees C; analyte species are released and transported to flame-heated quartz atom cell where the atomic signal is formed. In our study, interferences have been investigated in detail during Bi determination by hydride generation, both with and without trap in the same HGAAS system. Interferent/analyte (mass/mass) ratio was kept at 1, 10 and 100. Experiments were designed for carrier solutions having 1.0M HNO(3). Interferents such as Fe, Mn, Zn, Ni, Cu, As, Se, Cd, Pb, Au, Na, Mg, Ca, chloride, sulfate and phosphate were examined. The calibration plot for an 8.0 mL sampling volume was linear between 0.10 microg L(-1) and 10.0 microg L(-1) of Bi. The detection limit (3s/m) was 25 ng L(-1). The enhancement factor for the characteristic concentration (C(o)) was found to be 21 when compared with the regular system without trap, by using peak height values. The validation of the procedure was performed by the analysis of the certified water reference material and the result was found to be in good agreement with the certified values at the 95% confidence level.

Separation/Preconcentration of Zn(II), Cu(II), and Cd(II) by Saccharomyces carlsbergensis Immobilized on Silica Gel 60 in Various Samples

Abstract This study presents a solid phase extraction procedure based on column biosorption of Zn(II), Cu(II), and Cd(II) ions on Saccharomyces carlsbergensis immobilized on silica gel 60. The analytes were determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for the quantitative recovery of the analytes, including pH, amount of solid‐phase, eluent type and flow rate of sample solution were examined. The effect of interfering ions on the recovery of the analytes was also investigated. Under the optimum conditions, recoveries of Zn(II), Cu(II), and Cd(II) were 99±2%, 98±2%, and 100±2% at 95% confidence level, respectively for spiked water samples. The analytical detection limits for Zn(II), Cu(II), and Cd(II) were 1.14, 1.66, and 1.48 ng mL−1, respectively. The validation of the method was checked by the analysis of standard reference material (Tea leaves GBW‐07605) and spiked water, samples. The proposed method was applied for the determination of analytes in green onion, parsley, dam water, lake water, and tap water samples. The analytes has been determined in real samples with relative error lower than 8% and relative standard deviation lower than 10%.

Indium determination using slotted quartz tube-atom trap-flame atomic absorption spectrometry and interference studies

Sensitivity enhancement of indium determination by flame atomic absorption spectrometry (FAAS) was achieved; using a slotted quartz tube (SQT-FAAS) and slotted quartz tube atom trap (SQT-AT-FAAS). SQT was used as an atom trap (AT) where the analyte is accumulated in its inner wall prior to re-atomization. The signal is formed after re-atomization of analyte on the trap surface by introduction of 10 μL of isobutyl methyl ketone (IBMK). Sensitivity was improved 400 times using SQT-AT-FAAS system with respect to conventional FAAS and 279 times with respect to SQT-FAAS without any collection. Characteristic concentration (C(0)) and limit of detection values were found to be 3.63 ng mL(-1) and 2.60 ng mL(-1), respectively, using a sample flow rate of 7.0 mL min(-1) and a collection period of 5.0 min. In addition, interference effects of some elements on indium signal were studied. In order to characterize indium species trapped, X-ray Photoelectron Spectrometry (XPS) was utilized and it was found that indium was collected on the inner surface of SQT as In(2)O(3). The accuracy of the procedure was checked to determine indium in the standard reference material (Montana Soil, SRM 2710).

Preconcentration of cobalt using Amberlyst 36 as a solid-phase extractor and its determination in various environmental samples by flame atomic absorption spectrometry

A new and simple column-solid-phase extraction method has been developed to separate and preconcentrate trace cobalt in water and soil prior to its determination by flame atomic absorption spectrometry (FAAS). Different factors such as pH of sample solution, sample volume, amount of resin, flow rate of aqueous solution, volume and concentration of eluent, and matrix effects for preconcentration were optimized. Under optimized experimentally established conditions, an analytical detection limit of 0.44 µg L−1, precision (RSD) of 1.9%, enrichment factor of 200, and capacity of resin of 82 mg g−1 were obtained. The method was applied for cobalt determination by FAAS in tap water, natural drinking water, soil, and roadside dust samples. The accuracy of the method is confirmed by analysing standard reference material (Montana Soil, SRM 2711).

Determination of lead and copper in chewing gum samples by electrothermal-flame atomic absorption spectrometry using various chemical modifiers and arsenic by hydride generation

Abstract Lead and copper in chewing gum samples were determined by electrothermal atomic absorption spectrometry (ETAAS) with Zeeman background correction using various chemical modifiers and by flame atomic absorption spectrometry (FAAS) using 2% m/v ammonium pyrrolidine dithiocarbamate (APDC) complexing reagent in methyl isobuthyl keton (MIBK). Arsenic in samples was determined by hydride generation atomic absorption spectrometry (HGAAS). In order to decrease the interferences in sample matrix by ETAAS, Pd, Pt, W, Mo, Mg, PO 4 3− , their mixtures and W+Pd+tartaric acid (TA) have been tested as matrix modifiers in sample solutions. Modifiers have been compared in terms of pyrolysis temperature, atomization and background profiles of analytes. W+Pd+TA modifier mixture found as preferable was used for the determination of analytes by ETAAS. The reliability of the procedures was verified by analyzing several certified reference materials (CRMs). Detection limits of Pb and Cu determined by ETAAS and As determined by HGAAS were 1.2, 0.8 and 3.0 μg l −1 for Pb, Cu and As, respectively.

Determination of Cadmium(II) in Water and Soil Samples after Preconcentration with a New Solid Phase Extractor

Abstract A new simple and reliable method has been developed to separate and preconcentrate trace cadmium ion from water and soil samples for subsequent measurement by flame atomic absorption spectrometry (FAAS). Cadmium ions adsorbed quantitatively on Amberlyst 36 cation exchange resin were eluted with a 5 mL of 3 mol/L hydrochloric acid solution. Different factors and matrix effects for the preconcentration step were examined. The analytical figures of merit for the determination of cadmium are as follows: analytical detection limit, 0.51 µg/L; precision (RSD), 2.9%; enrichment factor, 200; capacity of resin 192 mg/g. The method was applied for cadmium determination in tap water, natural drinking water, soil, and roadside dust samples. The accuracy of the method is confirmed by analyzing standard reference material (Montana Soil, SRM 2711).

Determination of Copper in Water and Walnuts by Solid Phase Extraction and Slotted Quartz Tube Flame Atomic Absorption Spectrometry

ABSTRACT Cu(II) was separated and preconcentrated using solid phase extraction and a slotted quartz tube (SQT) and determined in drinking water and walnuts by flame atomic absorption spectrometry. The procedure is based on the sorption of copper(II) on a column filled with a resin followed by elution with 5 mL of 3 mol L−1 nitric acid in the first preconcentration step. To increase the sensitivity of system, the preconcentration parameters for copper(II) were optimized. The SQT was used as the second preconcentration step to further improve the sensitivity. The enrichment factor and detection limits were 640 and 0.23 µg L−1, respectively. Another advantage of this method is the presence of a wide pH range for copper(II) sorption with high effectiveness in acidic media. The accuracy of method was confirmed by the analysis of a spinach leaves certified reference material (NIST 1570a).

Determination of Adsorption Characteristics of Orange Peel Activated with Potassium Carbonate for Chromium(III) Removal

In this study, Cr (III) removal from aqueous solutions was investigated by using the batch adsorption method. An orange peel activated with potassium carbonate (OPAPC) was used as the adsorbent. In order to determine optimum adsorption conditions, adsorbent concentration (2-15 g/L), pH (3-7), temperature (298-318 K), contact time (10-270 min) and initial concentration of Cr (III) (5-50 mg/L) were investigated for Cr (III) removal from aqueous solutions using OPAPC. The equilibrium data were evaluated using the Langmuir and Freundlich model equations and the kinetic data were evaluated with pseudo first and second order kinetic models. In addition, the adsorption thermodynamics of the proposed method in optimum conditions was investigated.

Inorganic arsenic speciation by hydride generation atomic absorption spectrometry in water samples collected from some regions of Turkey

The determination of inorganic arsenic species in water samples from Ankara, _ Izmir and Burdur was done by using hydride generation atomic absorption spectrometry (HGAAS) with controlled pH and redox chemistry for speciation of As (III) and As (V). Specific trivalent arsenic is determined in water samples prepared in 0.10mol L 1 HCl with the usage of 1.0% (w/v) sodium tetrahydroborate (NaBH4) as reductant solution. The determination of total arsenic is done by reduction of As (V) to As (III) by means of 0.50% (w/v) ascorbic acid and 1.0% (w/v) potassium iodide (KI) in the 0.10molL 1 HCl in water samples. For this purpose, by using 0.1mol L 1 HCl at which As (V) did not give any signal while As (III) gave a signal in this acidity. Furthermore 1.0% (w/v) KI and 0.50% (w/v) ascorbic acid were added in water samples which were prepared in the 0.10mol L 1 HCl. The detection limit for this study is 0.29 ngmL 1 for As (III) and linear range of calibration plot is in the range from 1.6 to 16 ngmL . In order to check the accuracy of the method, certified reference material, CRM-TMDW trace metals in drinking water, mgL 1 was employed; the result was found to be in good agreement with the certified value at the 95% confidence level.