Yasemin Bakircioglu

Biosorption of lead by filamentous fungal biomass-loaded TiO2 nanoparticles.

In this study filamentous fungal biomass-loaded TiO(2) nanoparticles were used for the biosorption of lead(II) ions by flow-injection system coupled to flame atomic absorption spectrometry. The effects of pH, sample volume, loading and elution flow rates, eluent type and volume on the recovery of lead were investigated. Lead ions were sorbed on a biosorbent minicolumn at pH 4.0 followed by an elution step using 288 microL of 1.0 mol/L hydrochloric acid solution. The limit of detection was 0.78 microg/L. The validation of the described procedure was performed by the analysis of certified reference material (NRC-CNRC NASS-5 seawater). Finally, the presented biosorption procedure was applied to the determination of lead in tap water and seawater samples.

Concentration of cadmium, copper and zinc using water soluble polyacrylic acid polymer

Abstract In this study, a simple method was developed to use water soluble polymer, polyacrylic acid, for the separation and pre-concentration of trace Cd, Cu and Zn prior to their analysis by flame atomic absorption spectrometry. For this purpose, the sample and poly-acrylic acid were mixed and the metal-bound polymer was precipitated by the addition of acetone. The precipitate was separated and dissolved in a minimum amount of water and aspirated into a flame AAS. The method was compared with traditional water insoluble sorbents in all aspects. The technique described is fast, simple, precise and inexpensive. Blank values were low and recoveries were 96.5% for Cd, 99.7% for Cu and 98.0% for Zn. Detection limits (3σ) were 1.8 μg l−1 for Cd, 2.5 μg l−1 for Cu, and 2.2 μg l−1 for Zn.

Solid Phase Extraction of Bismuth and Chromium by Rice Husk

Abstract A major agricultural waste, rice husk and its ash were used for the preconcentration and separation of bismuth and chromium prior to their determination by flame atomic absorption spectrometry (FAAS) and their sorption properties with respect to bismuth and chromium from water samples were investigated. For this purpose, rice husk was thermally treated at 300°C for one hour and 600°C for ten hours in a muffle furnace. The effects of various experimental conditions on retention and elution efficiencies of studied elements for untreated rice with husk, untreated and thermally treated rice husk were investigated by applying batch and column methods. The analyte elements were quantitatively collected on rice with husk, the untreated and thermally treated rice husk at 300°C if the pH is above 3. The analyte elements retained on the rice with husk, rice husk or its ash were completely recovered by means of 2.0 M hydrochloric acid. Maximum chromium adsorption capacities of untreated rice with husk (URH), rice husk (RH), rice husk ash heated at 300°C (RHA-300) and 600°C (RHA-600) are 0.12, 0.50, 19.09 and 6.49 mg Cr/g adsorbent, respectively and 0.47, 294, 18.34 and 4.90 mg Bi/g adsorbent, respectively. When RHA-300 was used which is the most suitable adsorbent of all, detection limits (3 δ) were 1.3 µg/L for Bi and 1.5 µg/L for Cr. The relative standard deviations for the determinations were found to be 1.0–7.9%. The results showed that RHA especially heated at 300°C could be used as an efficient and cheap adsorbent for the removal of some heavy metals from the natural water samples and for the preconcentration and separation of bismuth and chromium prior to their determination by flame atomic absorption spectrometry.

Determination of Some Trace Heavy Metals in Some Water Samples by FAAS After Their Preconcentration Using DETA

Abstract Diethylenetriamine, DETA polymer was used as a preconcentration of cobalt, iron and nickel prior to their determination by flame atomic absorption spectrometry (FAAS). Both batch and column methods were used for the separation and concentration of above metals. These metals were quantitatively retained on the proposed adsorbent at pH 2, then were quantitatively eluted with 2 M hydrochloric acid or nitric acid. The recoveries of metal ions were greater than 98%. Detection limits (3 δ) were 1.5 µg/L for Co, 2.1 µg/L for Fe and 1.9 µg/L for Ni. The relative standard deviations for the determinations were found to be 1.0–8.8%. The effect of Na on the preconcentration of trace metals has also been investigated. The method was applied to tap, ground and lake water samples.

Evaluation of Syringe‐Connected Minicolumn Technique for Preconcentration of Some Trace Elements Using Chromosorb‐103 and Determination by Flame Atomic Absorption Spectrometry

Abstract A syringe‐connected minicolumn (SCM) technique has been developed for preconcentration and enrichment of cobalt, iron, and lead in river‐water samples prior to their determination by flame atomic absorption spectrometry (FAAS). The proposed technique is substituted for the classical batch and column techniques all of which are off‐line methods. The method proposed was compared with the column technique with respect to easiness, rapidness, simplicity and some analytic performances such as recovery, precision, accuracy and risk of contamination. The minicolumn was filled with Chromosorb‐103 as a sorbent. In order to retain the analyte elements, the sample solution was drawn into the syringe and discharged back passing through the sorbent in the minicolumn. The analyte elements were quantitatively retained at pH ≥4 if they were complexed with ammonium pyrrolidine dithiocarbamate (APDC) prior to passing through to the sorbent. The analytes sorbed on the minicolumn was then eluted with 1.0 mol L−1 HNO3 in acetone again drawing and discharging the eluent. Optimum flow rates of sample or eluent for sorption and elution procedure were 20 mL min−1 for both drawing and discharging cases. The proposed technique was successfully applied to the determination of analytes in certified reference material and spiked river‐water samples. The recoveries of analytes from certified reference material (Bovine liver) and river‐water samples were quantitative and reproducible (>96%, with relative standard deviation (RSD) of 1–5%). The developed technique is simple, fast, and accurate. Detection limits (3σ) were 4.8 µg L−1 for Co, 14 µg L−1 for Fe, and 15 µg L−1 for Pb. Very high preconcentration factors up to 200‐fold could be achieved.

DETERMINATION OF CADMIUM, COPPER, AND ZINC BY FLAME ATOMIC ABSORPTION SPECTROMETRY AFTER PRECONCENTRATION USING A DETA (DIETHYLENETRIAMINE) POLYMER

An atomic absorption spectrometric method with a preconcentration and separation procedure using a DETA (diethlyenetriamine) polymer is proposed for the determination of Cd, Cu and Zn. The influence various experimental condition on retention and elution efficiencies of the analyte were investigated by applying batch and column techniques. All investigated elements were quantitatively retained at pH 3, then were completely recovered by means of nitric acid. The loading capacity of the DETA polymer is 5.2 mg Cu2+/g polymer. A contact time of one minutes is sufficient for quantitative retention and elution which is shorter than for many other sorbents. In the presence of sodium chloride up to 0.5% the analyte elements were quantitatively separated and recovered.

Online solid phase preconcentration using EGDMA–MAA copolymer for lead determination by FAAS

A Ethylene glycol dimethacrylate (EGDMA) methacrylic acid (MAA) resin was used for preconcentration of lead at trace levels in water samples. For this purpose, a flow-injection, solid phase extraction method was developed for the determination of lead by flame atomic absorption spectrometry. Lead ions were sorbed on a EGDMA–MAA column at pH 4, followed by an elution step using 288 µL of 4.0 M nitric acid solution and determination by flame atomic absorption spectrometry. Optimum conditions for quantitative sorption involving the pH, sample volume, loading and elution flow rates, eluent type, and volume were investigated. A 868-fold enrichment factor could be reached. The detection limit for the water samples, estimated from the noise on the signal obtained for 250 mL of 10 µg L−1 loaded at 4.9 mL min−1 was 1.04 µg L−1. The method was applied for lead determination in river water samples collected in Edirne, Turkey. Recoveries of spiked solutions (10 µg L−1) to river water samples were quantitative. Finally, the method was validated by the analysis of certified reference material SRM 2704 (Buffalo River Sediment).

Elemental analysis of urban aerosols collected in budapest (Hungary) and wuhan (China)

PM10 fractions of urban aerosols were collected on quartz fiber filters in downtown Budapest and Wuhan applying high and low volume samplers, respectively. Following a microwave-assisted acidic extraction of aerosols in aqua regia at a temperature of 210°C and a pressure of 75 bars for 20 min, the concentrations of the extracted elements Ag, Bi, Cd, Co, Cr, Cu, Fe, Ga, Li, Mn, Mo, Ni, Pb, Pt, Rb, Sb, Sn, Sr, Te, Tl, U, V, and Zn were determined by an inductively coupled plasma sector field mass spectrometer. Considering the available health limit values (Cd 5, Cr 50, Pb 500, Ni 20 ng m−3), it was established that the concentrations of Cd, Ni, and Pb in the Chinese samples were in most cases above or near to the limit values during the 12 month long sampling period. In addition, the mass concentration of the PM10 fraction collected in Wuhan in all cases exceeded the daily health criteria guideline value (50 µg m−3) and it was about three times higher than in Budapest. From the health point of view, the situation in Budapest is better due to the lower concentration of toxic elements and carbon compounds in the air.