A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotome... more A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Escherichia coli immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd by E. coli immobilized on sepiolite were 99.19 0.6, 98.29 0.6, 98.19 0.5, 97.29 0.8 and 98.2 90.4% at 95% confidence level, respectively. The adsorption capacity of E. coli immobilized on sepiolite was found as 0.148, 0.064, 0.098, 0.134 and 0.088 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in alloys (NBS SRM 85b). Trace metals have been determined with relative error lower than 10%.
A rapid, sensitive and accurate method for the separation, preconcentration and determination of ... more A rapid, sensitive and accurate method for the separation, preconcentration and determination of Cr(III) and Cr(VI) in water samples is described. Chromium species can be separated by biosorption on Saccharomyces cerevisiae immobilized on sepiolite and determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for separation and preconcentration (pH, bed height, flow rate and volume of sample solution) were evaluated. Recovery of the chromium was 96.3+/-0.2% at 95% confidence level. The breakthrough capacity of the adsorbent was found as 228 mumol g(-1) for Cr(III). The proposed method was applied successfully to the determination of Cr(III) and Cr(VI) in spiked and river water samples.
A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic abs... more A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01±0.06%, 98.8±0.5%, 98.0±0.4%, 96.4±0.8% and 94.8±0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.
The penetration of three herbicides through isolated potato periderm (PM) and pear fruit cuticula... more The penetration of three herbicides through isolated potato periderm (PM) and pear fruit cuticular membranes (PFCM) as their commercial formulations was examined in two separate experimental methods involving infinite and finite dose systems. The ...
Fresenius Journal of Analytical Chemistry, Feb 5, 1999
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution me... more By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 µmol/g for copper, 128 µmol/g for zinc and 97 µmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.
Bu çalışmada kolon yöntemi kullanılarak Fe{2} iyonlarının Saccharomyces cerevisiae immobilize edi... more Bu çalışmada kolon yöntemi kullanılarak Fe{2} iyonlarının Saccharomyces cerevisiae immobilize edilmiş ponza taşına adsorpsiyon şartları araştırıldı. Bu amaçla; adsorpsiyona çözelti pH sının, iyon başlangıç derişiminin ve adsorplanan iyonların geri kazanılması için uygun çözelti türü ve derişiminin etkisi araştırıldı. Maksimum adsorpsiyonun sağlandığı pH değerinin 5 olduğu belirlendi. Optimum pH değerinde, adsorbanın metal tutma kapasitesi 60 \mu g/mL başlangıç derişiminde 1,81mg/g dır. Desorpsiyona HC1, NaCl, NH4C1 ve EDTA çözeltilerinin etkisi araştırıldı. En uygun çözeltinin 0,2 M'lık EDTA çözeltisi olduğu gözlendi. 0,2 M EDTA çözeltisi ile %98 oranında desorpsiyon sağlandı.In this study, the adsorption conditions of Fe{2} ions on Saccharomyces cerevisae immobilized pumice stone were investigated by column method. In order to perform this aim, the effect of solution pH value, initial concentration of ions and suitable solution and concentration for recovery of adsorbed ions we...
The adsorption of Cu, Zn and Ni on to formaldehyde cross-linked Saccharomyces cerevisiae immobili... more The adsorption of Cu, Zn and Ni on to formaldehyde cross-linked Saccharomyces cerevisiae immobilized on pumice stone was investigated. Maximum adsorption was occurred at pH 6 for all elements studied. The effect of mixing time and the initial concentration of metal ion on the adsorption of metal ions were also investigated. 1 mol 1-1 of HCl, KCl (pH 2) and NaCl (pH 2) solutions were tested for desorption and 1 mol 1-1 of KCl (pH 2) solution was found to be appropriate for the desorption of all metals studied. The desorption was 89.2% for Cu, 89.8% for Zn and 87.0 for Ni. The metal capacity of immobilized cell biomass (quantity of metals accumulatad by one gram biomass) was found as 2.09, 2.24 and 3.18 mg g-1 dry cell biomass for Zn, Cu and Ni, respectively
Objective: Cancer cells choose their metabolic pathway depending on the oxygen content and substr... more Objective: Cancer cells choose their metabolic pathway depending on the oxygen content and substrate concentration of the medium. A wide spectrum of therapeutic agents regulating the energy metabolism of cancer cells are in still in use. Cytosine arabinoside (Ara-C) is a pyrimidine analogue used in the treatment of acute myeloid leukemia (AML) and simvastatin is an inhibitor of HMG-CoA (3-hydroxy-3-methyl-glutaryl-CoA) reductase, which regulates cholesterol biosynthesis. Thus, this study aimed to assess the energy metabolism of HL-60 promyelocytic leukemia cells and healthy white blood cells, additionally to determine the effects of simvastatin and Ara-C, alone or in combination on the energy metabolism of these cells. Materials and Methods: Healthy white blood cells, untreated and treated HL-60 promyolocytic leukemia cell lines were incubated for 4 hours with radiolabelled glucose. Following incubation, lactate, which is one of the end products of the carbohydrate catabolism, and r...
In this study, the adsorption conditions of Fe ions on Saccharomyces cerevisae immobilized pumice... more In this study, the adsorption conditions of Fe ions on Saccharomyces cerevisae immobilized pumice stone were investigated by column method. In order to perform this aim, the effect of solution pH value, initial concentration of ions and suitable solution and concentration for recovery of adsorbed ions were investigated.At pH 5, the maximum adsorption was obtained. At optimal pH value, adsorption capacity of sorbent for metal was obtained as 1,81 mg.g, when initial concentration was 60 mg.ml. Influence of HCl, NaCl, NH4Cl and EDTA solutions on desorption were investigated and maximum recovery was achieved by 0,2M EDTA solution. Desorption were 98% level provided by 0,2 M EDTA solution.
Education of analytical chemistry as a serving discipline is frequently and effective contributin... more Education of analytical chemistry as a serving discipline is frequently and effective contributing with other scientific and social sciences in building up scientific knowledge and skill. It has to cope with the increasing importance of analytical chemistry and its role in every aspect of life in the modern society. The role of analytical chemistry and its effect on consumer protection, health, environment and economy is increasing tremendously specially in the new economic system and trade agreements. Education of anal. chem. thus, has to cope with the societal needs and the demands of the labor market both nationally and globally so that we can have well informed, trained and capable specialists that can compete in different industries, laboratories, control units and research groups.
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution me... more By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 µmol/g for copper, 128 µmol/g for zinc and 97 µmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.
The Effects of Ara-C, Simvastatin and combo therapy on energy metabolism of HL-60 promyolocytic l... more The Effects of Ara-C, Simvastatin and combo therapy on energy metabolism of HL-60 promyolocytic leukemia cell lines [HL-60 lösemi hücrelerinde Ara-C ve Simvastatinin tek tek ve kombine kullanımlarının enerji metabolizması üzerindeki etkileri]
A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotome... more A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Escherichia coli immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd by E. coli immobilized on sepiolite were 99.19 0.6, 98.29 0.6, 98.19 0.5, 97.29 0.8 and 98.2 90.4% at 95% confidence level, respectively. The adsorption capacity of E. coli immobilized on sepiolite was found as 0.148, 0.064, 0.098, 0.134 and 0.088 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in alloys (NBS SRM 85b). Trace metals have been determined with relative error lower than 10%.
A rapid, sensitive and accurate method for the separation, preconcentration and determination of ... more A rapid, sensitive and accurate method for the separation, preconcentration and determination of Cr(III) and Cr(VI) in water samples is described. Chromium species can be separated by biosorption on Saccharomyces cere6isiae immobilized on sepiolite and determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for separation and preconcentration (pH, bed height, flow rate and volume of sample solution) were evaluated. Recovery of the chromium was 96.39 0.2% at 95% confidence level. The breakthrough capacity of the adsorbent was found as 228 mmol g − 1 for Cr(III). The proposed method was applied successfully to the determination of Cr(III) and Cr(VI) in spiked and river water samples.
Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and d... more Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and determined by flame atomic absorption spectrophotometry (FAAS). Preconcentration studies were conducted by the column method. Effect of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Fe and Ni were 95+/-1 and 99.5+/-0.1%, respectively, at 95% confidence level. The breakthrough capacities of analytes were also investigated and found to be 0.042 mmol g(-1) for Fe and 0.055 mmol g(-1) for Ni. The proposed method was applied to the determination of iron and nickel in brass (NBS SRM 37e). The detection limit of iron and nickel were found as 0.065 and 0.087 mug ml(-1), respectively. The direct determination of trace metals by flame atomic absorption spectrometry (FAAS) is limited and difficult because of low concentration and/or matrix interferences. The proposed method is excellent for the determination of trace metal in matrixes, such as metal alloys.
Aldicarb is a carbamate pesticide that is widely used throughout the world in the protection of c... more Aldicarb is a carbamate pesticide that is widely used throughout the world in the protection of crops (eg cotton, nuts, potatoes, onion, tobacco, sugar beet and sugar cane). In Turkey, especially in the C Ë ukurova region, it is used for the control of the cotton white¯y (Bemisia tabaci) which attacks cotton plants cultivated in this region. Aldicarb contamination in surface and ground water is a serious problem in several countries, partly due to its high water solubility. It is also highly toxic to mammals. In order to overcome these problems, microspheres of aldicarb were prepared using carboxymethyl cellulose (CMC) as the biodegradable support material cross-linked with aluminium chloride. A strong hysteresis behaviour was observed upon drying and reswelling. Encapsulation ef®ciency was in the range 12±23% and aldicarb contents of 5.7±10.3 mg per 100 mg of microspheres was achieved. In vitro release was distinctly Fickian, and Higuchi constants were very close to 0.5. Release in pots revealed that only one sample had a release capability for more than four weeks. In the cotton plot much longer durations of release (more than seven weeks) were observed while a commercial granular formulation released its content immediately. It was thus possible to construct a controlled pesticide release system that prolonged the bioavailability to about eight weeks.
A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic abs... more A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01±0.06%, 98.8±0.5%, 98.0±0.4%, 96.4±0.8% and 94.8±0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.
A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotome... more A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Escherichia coli immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd by E. coli immobilized on sepiolite were 99.19 0.6, 98.29 0.6, 98.19 0.5, 97.29 0.8 and 98.2 90.4% at 95% confidence level, respectively. The adsorption capacity of E. coli immobilized on sepiolite was found as 0.148, 0.064, 0.098, 0.134 and 0.088 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in alloys (NBS SRM 85b). Trace metals have been determined with relative error lower than 10%.
A rapid, sensitive and accurate method for the separation, preconcentration and determination of ... more A rapid, sensitive and accurate method for the separation, preconcentration and determination of Cr(III) and Cr(VI) in water samples is described. Chromium species can be separated by biosorption on Saccharomyces cerevisiae immobilized on sepiolite and determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for separation and preconcentration (pH, bed height, flow rate and volume of sample solution) were evaluated. Recovery of the chromium was 96.3+/-0.2% at 95% confidence level. The breakthrough capacity of the adsorbent was found as 228 mumol g(-1) for Cr(III). The proposed method was applied successfully to the determination of Cr(III) and Cr(VI) in spiked and river water samples.
A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic abs... more A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01±0.06%, 98.8±0.5%, 98.0±0.4%, 96.4±0.8% and 94.8±0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.
The penetration of three herbicides through isolated potato periderm (PM) and pear fruit cuticula... more The penetration of three herbicides through isolated potato periderm (PM) and pear fruit cuticular membranes (PFCM) as their commercial formulations was examined in two separate experimental methods involving infinite and finite dose systems. The ...
Fresenius Journal of Analytical Chemistry, Feb 5, 1999
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution me... more By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 µmol/g for copper, 128 µmol/g for zinc and 97 µmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.
Bu çalışmada kolon yöntemi kullanılarak Fe{2} iyonlarının Saccharomyces cerevisiae immobilize edi... more Bu çalışmada kolon yöntemi kullanılarak Fe{2} iyonlarının Saccharomyces cerevisiae immobilize edilmiş ponza taşına adsorpsiyon şartları araştırıldı. Bu amaçla; adsorpsiyona çözelti pH sının, iyon başlangıç derişiminin ve adsorplanan iyonların geri kazanılması için uygun çözelti türü ve derişiminin etkisi araştırıldı. Maksimum adsorpsiyonun sağlandığı pH değerinin 5 olduğu belirlendi. Optimum pH değerinde, adsorbanın metal tutma kapasitesi 60 \mu g/mL başlangıç derişiminde 1,81mg/g dır. Desorpsiyona HC1, NaCl, NH4C1 ve EDTA çözeltilerinin etkisi araştırıldı. En uygun çözeltinin 0,2 M'lık EDTA çözeltisi olduğu gözlendi. 0,2 M EDTA çözeltisi ile %98 oranında desorpsiyon sağlandı.In this study, the adsorption conditions of Fe{2} ions on Saccharomyces cerevisae immobilized pumice stone were investigated by column method. In order to perform this aim, the effect of solution pH value, initial concentration of ions and suitable solution and concentration for recovery of adsorbed ions we...
The adsorption of Cu, Zn and Ni on to formaldehyde cross-linked Saccharomyces cerevisiae immobili... more The adsorption of Cu, Zn and Ni on to formaldehyde cross-linked Saccharomyces cerevisiae immobilized on pumice stone was investigated. Maximum adsorption was occurred at pH 6 for all elements studied. The effect of mixing time and the initial concentration of metal ion on the adsorption of metal ions were also investigated. 1 mol 1-1 of HCl, KCl (pH 2) and NaCl (pH 2) solutions were tested for desorption and 1 mol 1-1 of KCl (pH 2) solution was found to be appropriate for the desorption of all metals studied. The desorption was 89.2% for Cu, 89.8% for Zn and 87.0 for Ni. The metal capacity of immobilized cell biomass (quantity of metals accumulatad by one gram biomass) was found as 2.09, 2.24 and 3.18 mg g-1 dry cell biomass for Zn, Cu and Ni, respectively
Objective: Cancer cells choose their metabolic pathway depending on the oxygen content and substr... more Objective: Cancer cells choose their metabolic pathway depending on the oxygen content and substrate concentration of the medium. A wide spectrum of therapeutic agents regulating the energy metabolism of cancer cells are in still in use. Cytosine arabinoside (Ara-C) is a pyrimidine analogue used in the treatment of acute myeloid leukemia (AML) and simvastatin is an inhibitor of HMG-CoA (3-hydroxy-3-methyl-glutaryl-CoA) reductase, which regulates cholesterol biosynthesis. Thus, this study aimed to assess the energy metabolism of HL-60 promyelocytic leukemia cells and healthy white blood cells, additionally to determine the effects of simvastatin and Ara-C, alone or in combination on the energy metabolism of these cells. Materials and Methods: Healthy white blood cells, untreated and treated HL-60 promyolocytic leukemia cell lines were incubated for 4 hours with radiolabelled glucose. Following incubation, lactate, which is one of the end products of the carbohydrate catabolism, and r...
In this study, the adsorption conditions of Fe ions on Saccharomyces cerevisae immobilized pumice... more In this study, the adsorption conditions of Fe ions on Saccharomyces cerevisae immobilized pumice stone were investigated by column method. In order to perform this aim, the effect of solution pH value, initial concentration of ions and suitable solution and concentration for recovery of adsorbed ions were investigated.At pH 5, the maximum adsorption was obtained. At optimal pH value, adsorption capacity of sorbent for metal was obtained as 1,81 mg.g, when initial concentration was 60 mg.ml. Influence of HCl, NaCl, NH4Cl and EDTA solutions on desorption were investigated and maximum recovery was achieved by 0,2M EDTA solution. Desorption were 98% level provided by 0,2 M EDTA solution.
Education of analytical chemistry as a serving discipline is frequently and effective contributin... more Education of analytical chemistry as a serving discipline is frequently and effective contributing with other scientific and social sciences in building up scientific knowledge and skill. It has to cope with the increasing importance of analytical chemistry and its role in every aspect of life in the modern society. The role of analytical chemistry and its effect on consumer protection, health, environment and economy is increasing tremendously specially in the new economic system and trade agreements. Education of anal. chem. thus, has to cope with the societal needs and the demands of the labor market both nationally and globally so that we can have well informed, trained and capable specialists that can compete in different industries, laboratories, control units and research groups.
By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution me... more By using the adsorbent Saccharomyces cerevisiae immobilized on sepiolite an adsorption-elution method was developed for the preconcentration of Cu, Zn, and Cd followed by flame atomic absorption spectrometry (FAAS). Recoveries were 98.3 ± 0.4% for Cu, 94.2 ± 0.3% for Zn, and 99.04 ± 0.04% for Cd at 95% confidence level obtained by the column method. The influence of sea water matrix elements on the separation of the trace elements was also assessed by using the column procedure. The breakthrough capacities were found to be 74 µmol/g for copper, 128 µmol/g for zinc and 97 µmol/g for cadmium. After optimization the proposed method was applied to the trace metal determination in sea and river water.
The Effects of Ara-C, Simvastatin and combo therapy on energy metabolism of HL-60 promyolocytic l... more The Effects of Ara-C, Simvastatin and combo therapy on energy metabolism of HL-60 promyolocytic leukemia cell lines [HL-60 lösemi hücrelerinde Ara-C ve Simvastatinin tek tek ve kombine kullanımlarının enerji metabolizması üzerindeki etkileri]
A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotome... more A method for the determination of Cu, Zn, Fe, Ni and Cd by flame atomic absorption spectrophotometry (FAAS) after preconcentrating on a column containing Escherichia coli immobilized on sepiolite has been developed. Optimum pH values, amount of adsorbent, elution solution and flow rate have been obtained for the elements studied. The effect of interfering ions on the recovery of the analytes has also been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd by E. coli immobilized on sepiolite were 99.19 0.6, 98.29 0.6, 98.19 0.5, 97.29 0.8 and 98.2 90.4% at 95% confidence level, respectively. The adsorption capacity of E. coli immobilized on sepiolite was found as 0.148, 0.064, 0.098, 0.134 and 0.088 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in alloys (NBS SRM 85b). Trace metals have been determined with relative error lower than 10%.
A rapid, sensitive and accurate method for the separation, preconcentration and determination of ... more A rapid, sensitive and accurate method for the separation, preconcentration and determination of Cr(III) and Cr(VI) in water samples is described. Chromium species can be separated by biosorption on Saccharomyces cere6isiae immobilized on sepiolite and determined by flame atomic absorption spectrometry (FAAS). The optimum conditions for separation and preconcentration (pH, bed height, flow rate and volume of sample solution) were evaluated. Recovery of the chromium was 96.39 0.2% at 95% confidence level. The breakthrough capacity of the adsorbent was found as 228 mmol g − 1 for Cr(III). The proposed method was applied successfully to the determination of Cr(III) and Cr(VI) in spiked and river water samples.
Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and d... more Iron and nickel have been preconcentrated on Saccharomyces cerevisiae immobilized sepiolite and determined by flame atomic absorption spectrophotometry (FAAS). Preconcentration studies were conducted by the column method. Effect of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Fe and Ni were 95+/-1 and 99.5+/-0.1%, respectively, at 95% confidence level. The breakthrough capacities of analytes were also investigated and found to be 0.042 mmol g(-1) for Fe and 0.055 mmol g(-1) for Ni. The proposed method was applied to the determination of iron and nickel in brass (NBS SRM 37e). The detection limit of iron and nickel were found as 0.065 and 0.087 mug ml(-1), respectively. The direct determination of trace metals by flame atomic absorption spectrometry (FAAS) is limited and difficult because of low concentration and/or matrix interferences. The proposed method is excellent for the determination of trace metal in matrixes, such as metal alloys.
Aldicarb is a carbamate pesticide that is widely used throughout the world in the protection of c... more Aldicarb is a carbamate pesticide that is widely used throughout the world in the protection of crops (eg cotton, nuts, potatoes, onion, tobacco, sugar beet and sugar cane). In Turkey, especially in the C Ë ukurova region, it is used for the control of the cotton white¯y (Bemisia tabaci) which attacks cotton plants cultivated in this region. Aldicarb contamination in surface and ground water is a serious problem in several countries, partly due to its high water solubility. It is also highly toxic to mammals. In order to overcome these problems, microspheres of aldicarb were prepared using carboxymethyl cellulose (CMC) as the biodegradable support material cross-linked with aluminium chloride. A strong hysteresis behaviour was observed upon drying and reswelling. Encapsulation ef®ciency was in the range 12±23% and aldicarb contents of 5.7±10.3 mg per 100 mg of microspheres was achieved. In vitro release was distinctly Fickian, and Higuchi constants were very close to 0.5. Release in pots revealed that only one sample had a release capability for more than four weeks. In the cotton plot much longer durations of release (more than seven weeks) were observed while a commercial granular formulation released its content immediately. It was thus possible to construct a controlled pesticide release system that prolonged the bioavailability to about eight weeks.
A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic abs... more A method for the determination of Cu, Zn, Fe, Ni and Cd in geological samples by flame atomic absorption spectrophotometry (FAAS) after preconcentrating by Aspergillus niger immobilized on sepiolite has been developed. The column adsorption method was used for the preconcentration studies. Effects of pH, amount of adsorbent, elution solution, flow rate and interfering ions on the recovery of the analytes have been investigated. Recoveries of Cu, Zn, Fe, Ni and Cd on Aspergillus niger immobilized sepiolite were 98.01±0.06%, 98.8±0.5%, 98.0±0.4%, 96.4±0.8% and 94.8±0.6% at 95% confidence level, respectively. The breakthrough capacity of the adsorbent was found as 0.093, 0.078, 0.067, 0.085 and 0.102 mmol/g for Cu, Zn, Fe, Ni and Cd, respectively. The proposed method was applied to the determination of trace metals in geological samples, such as AGV-1, JG-1a and Wismuterz II. Trace metals have been determined with about 5% relative error.
Uploads
Papers by Mustafa Lale