In this investigation, titanium oxide plates were used as cathode for hydrogen production in the ... more In this investigation, titanium oxide plates were used as cathode for hydrogen production in the aqueous solutions of sulfuric acid, potassium hydroxide, acetic acid and ammonia hydroxides electrolytes separately. Gaseous hydrogen was produced at the cathode and oxygen at the anode. For this purpose, titanium plates were fabricated in acid solution by anodic oxidation. Microstructure of TiO 2 nanorod observation was conducted with scanning electron microscopy (SEM). The effects of operating conditions and the electrochemical test parameters, such as electrolytes concentration, temperature, and cell voltage were investigated. Also the performance of TiO 2 cathode was compared to zirconium oxide and graphite electrodes. The results show that the highly rated, hydrogen production performance on TiO 2 cathode has better than the other electrodes. The maximum rate of hydrogen production is by TiO 2 cathode 8.18 ml/ (h. cm 2). The cell efficiency for water electrolysis was reached 95% using titanium oxide electrode in 1.5 M H 2 SO 4 .
Rationale: Pesticides are poisonous substances or mixtures of dangerous chemicals used to prevent... more Rationale: Pesticides are poisonous substances or mixtures of dangerous chemicals used to prevent, dissuade, control, or eradicate insects, weeds, rodents, fungi, or other potentially dangerous organisms. Pesticides must be separated from complex matrices before analysis by performing the proper extraction, cleaning, and/or preconcentration processes. The QuEChERS method served as a matrix clean-up tool and the DLLME method preconcentrated the analytes for their determination at trace
Bulletin of Environmental Contamination and Toxicology, Nov 23, 2018
Antimony is known to have some adverse health effects on human health. Flame atomic absorption sp... more Antimony is known to have some adverse health effects on human health. Flame atomic absorption spectrometry (FAAS) is a widely used instrumental for the determination of antimony and other metals. However, it lacks the sensitivity to determine these metals at trace levels. This study was aimed at overcoming this setback by using hydrogen assisted T-shaped slotted quartz tube technique to preconcentrate and determine antimony by FAAS. All the system parameters were optimized to enhance the detection power of the system. Under the optimum experimental conditions, the limits of detection and quantification were found to be 0.75 and 2.49 µg L −1 , respectively with R 2 value of 0.9999. Accuracy of the developed method was validated by experimental results agreeing to the certified value of a standard reference material. Recovery studies were also carried out to determine the method's applicability to tap and mineral water samples, and the results obtained were appreciable.
This study aims to develop coating quality by using Flow Analysis (FA) technique in acid copper c... more This study aims to develop coating quality by using Flow Analysis (FA) technique in acid copper coating bath. The coating metal concentration of electrodeposition bath mixture, current density, coating time, distance between anode and cathode, temperature of bath mixture and pH are some of the factors which affect the coating quality. The coating metal concentration is the most important parameter. The metal concentration of electroplating bath solution decreases during the coating so coating quality also decreases. Bath mixture composition has been determined by analysing samples periodically according to the conventional industrial application. Much more time, effort and high financial cost are very necessary for this type of analysis. This paper represents a new method which determines the metal concentration of coating baths with flow analysis technique. The metal concentration is measured on-line with spectrophotometric technique which includes flow through cell according to the new method. This technique is very simple and the results can be taken easily. Firstly, the decrease in metal concentration is determined by the batch technique and then a sufficient amount of stock metal solution is added to the plating bath continuously by on-line system. The metal concentration of coating bath solution is kept at constant concentrations. This means that the coating metal quality does not
Background Presently, there is no validated method for stability-indicating related substances of... more Background Presently, there is no validated method for stability-indicating related substances of adenosine used in the treatment of cataracts and found in different combined eye drop products. Objective A stability-indicating related substances analytical method for adenosine used in the treatment of cataracts and found in different combined eye drop products should be developed and validated. Method A new reverse phase-HPLC method of determination for adenosine-related compounds has been developed and validated according to the International Council for Harmonisation. In this method, all impurities were easily detected for adenosine, which is found in combination with different active ingredients such as nicotinic acid and nicotinamide. The impurities obtained by a stress test were purified and their structures were characterized by mass spectroscopy (LC-QTOF-MS). Results The concentration range for linearity was evaluated as 0.06–4.27 µg/mL for adenosine, 0.15–4.27 µg/mL for uridine, 0.15–4.17 µg/mL for inosine, 0.13–4.35 µg/mL for guanosine, and 0.12–4.26 µg/mL for adenine. Good linearity was achieved for each component, and it was determined that the correlation coefficient (r) met the acceptance criterion r ≥ 0.99. The accuracy of the method was good-to-excellent recoveries at each concentration level (from LOQ to 120% of the specification limit) were achieved within the limit range of 80.0–120.0%, and RSD of recoveries was found below 10.0% for both formulations. Conclusions With this economical and simple method validated in accordance with the ICH Q2 (R1) guideline, a new method has been created for adenosine, which is suitable for routine analysis. Highlights The validated method is a very simple and suitable method for green chemistry without any pre-processing, and the structure of the impurities obtained as a result of stress studies was confirmed by LC-QTOF-MS.
Simple and fast spectrophotometric methods for the determination of the components of ternary mix... more Simple and fast spectrophotometric methods for the determination of the components of ternary mixtures of dyes have been proposed. For the simultaneous determination of Sunset Yellow (E110), Tartrazine (E102), and Ponceau4R (E124) in granulated drinks partial least square (PLS) method was applied to the spectrophotometric data in the range 400-600 nm, at 10 nm intervals. In the procedure 27 standard mixtures of three assayed compounds at three concentration levels were used. Absorbance measurements were performed in methanolic solutions. The results were compared with those obtained using a common derivative spectrophotometric procedure (zero-crossing technique). These procedures did not require any separation steps. Statistical evaluation of the method bias was performed. It was concluded that PLS method might be competitive with derivative procedure for the separation of ternary mixtures of dyes.
Metal adsorption studies are getting important and there are many functional adsorbents developed... more Metal adsorption studies are getting important and there are many functional adsorbents developed recently. Here, we report the synthesis of multifunctional PAMAM G2 (polyamidoamine) possessing methacryl, amine, hydroxyl and phosphonate groups used in free radical curing gel formulations. UV curable gel is conducted in the presence of acrylamide, bisacrylamide, and polyethylene glycol diacrylate. Adsorption study of the resulting novel sorbents (gels) are carried out with a series of metals. Through a comprehensive study, structure–property relationship of the series gels is conducted by using different amount of amine, hydroxyl, and/or phosphonate ester groups on the PAMAM G2. Selected metals are Cr3+, Fe3+, Ni2+, Cu2+, Ag+, and Cd2+ within a series of hard, intermediate, and soft ionic species. Adsorption study is carried out in pure water environment at neutral pH. Metal ions removal percentages and adsorption capacities of gel adsorbents are calculated by using atomic absorption spectroscopy. There is relationship between the overall functional groups presence in gel formulation and swelling densities for removing the metal ions. Introducing dendrimer into the gel formulation enhanced the metal ions adsorption against to Bare GEL formulation which do not possess dendrimer units. Consequently, the maximum removal efficiency has been obtained for Cr3+ and Fe3+.
In the present work, a method has been described for the determination of copper and lead by flam... more In the present work, a method has been described for the determination of copper and lead by flame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and coflotation. Purolite S-940, that is a strong cation exchanger, was used for preconcentration and separation of the trace metals as the first method. Optimum metal uptake conditions were investigated using batch systems. These optimum conditions are: pH, contact time, the initial metal concentration and the amount of resin. Using results obtained from experiments of optimum conditions, Cu and Pb in water samples which were taken from ISKI (Water Authority for Istanbul) Kagithane and ISKI Biiyilk9ekmece were enriched and determined by FAAS. The second method is a preconcentration and separation using hexamethylendithiocarbomate as a chelating agent for colloid flotation Cu and Pb from water. The influences arising from pH, nitric acid concentration, amount of analytes, and sample volume on the recoveries were assessed. Cu and Pb in water samples which were taken from ISKI Kagithane and ISKI Büyüksekmece were enriched and determined by FAAS.
An accurate, fast and simple method for determination of thallium in environmental water samples ... more An accurate, fast and simple method for determination of thallium in environmental water samples with Zeeman electrothermal atomic absorption spectrometry (ZETAAS) by previous flotation preconcentration is given. The possibility of using Co(III) dithiocarbamates as colloidal precipitate collectors for simultaneously flotation separation of Tl(I) and Tl(III) from water matrices was studied. The experiments showed that Co(HMDTC) 3 as a collector for flotation of both Tl species is far more effective than Co(HpDTC) 3. The limit of detection of Tl is 0.031 µg/l.
Two preconcentration techniques, ion exchange and fl otation, were used for the determination of ... more Two preconcentration techniques, ion exchange and fl otation, were used for the determination of zinc (Zn), nickel (Ni) and cadmium (Cd) in natural water samples. In the fi rst part of our work, the adsorption of zinc(II), nickel(II) and cadmium(II) on Lewatit TP 207 chelating resin containing iminodiacetate groups was studied at different pH values by a batch process. The effects of parameters such as amount of resin, contact time, pH and initial metal concentration on the ion exchange separation were investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions were also studied. The concentrations of metal ions were measured by batch techniques and with atomic absorption spectrometry analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir and Freundlich isotherms. The effi ciency of removal is higher for Ni and Zn than Cd ions. Here, we report the method that is applied for the sorption and separation of some toxic metals from the solutions. In the second part of our work, the fl otation technique was used for preconcentration. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC) 3 , as a fl otation collector for metals from natural waters was investigated. The fl otation method was compared with the ion exchange method. The recoveries of Zn, Cd and Ni from natural water samples were approximately 99 %. Our results showed that the two methods were very effective, but the fl otation results were higher than the ion exchange results. In the present study, a method was described for the determination of Zn, Ni and Cd by fl ame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and fl otation. Results of these two methods are compared. Analytical parameters such as precision and accuracy of methods were also studied. The equilibrium experimental results of Zn, Ni and Cd ions exchanged were fi tted by Langmuir-Freundlich adsorption isotherm models.
Two preconcentration techniques, ion exchange and fl otation, were used for the determination of ... more Two preconcentration techniques, ion exchange and fl otation, were used for the determination of zinc (Zn), nickel (Ni) and cadmium (Cd) in natural water samples. In the fi rst part of our work, the adsorption of zinc(II), nickel(II) and cadmium(II) on Lewatit TP 207 chelating resin containing iminodiacetate groups was studied at different pH values by a batch process. The effects of parameters such as amount of resin, contact time, pH and initial metal concentration on the ion exchange separation were investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions were also studied. The concentrations of metal ions were measured by batch techniques and with atomic absorption spectrometry analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir and Freundlich isotherms. The effi ciency of removal is higher for Ni and Zn than Cd ions. Here, we report the method that is applied for the sorption and separation of some toxic metals from the solutions. In the second part of our work, the fl otation technique was used for preconcentration. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC) 3 , as a fl otation collector for metals from natural waters was investigated. The fl otation method was compared with the ion exchange method. The recoveries of Zn, Cd and Ni from natural water samples were approximately 99 %. Our results showed that the two methods were very effective, but the fl otation results were higher than the ion exchange results. In the present study, a method was described for the determination of Zn, Ni and Cd by fl ame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and fl otation. Results of these two methods are compared. Analytical parameters such as precision and accuracy of methods were also studied. The equilibrium experimental results of Zn, Ni and Cd ions exchanged were fi tted by Langmuir-Freundlich adsorption isotherm models.
Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders... more Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders by first derivative spectrophotometry and by partial least-squares multivariate spectrophotometric calibration are described. These procedures do not require any separation step. These methods were applied to determine both colorants in commercial gelatin powders and the results obtained were compared. A good statistical agreement was obtained
ABSTRACT A classic analytical problem is the simultaneous determination of two or more compounds ... more ABSTRACT A classic analytical problem is the simultaneous determination of two or more compounds in the same sample without previous chemical separation. In this way derivative spectrophotometry is an anaytical technique of great utility and offers greater selectivity than normal spectrophotometry. The resolution of binary mixtures of compounds with overlapped spectra by derivative spectrophotometry is frequently made on the basis of zero-crossing measurements. A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the synthetic colorants sunset yellow (E-110) and erythrosine (E-127). The assay procedure for E-110 and E-127 in Premarin tablets involves extraction of the colorants from tablets with distilled water and measurement of first derivative absorbance values at 482.7 nm for E-127, then filtration from rough paper and measurement of D values at 526.3 nm for E-110. Linear correlations over the concentration ranges of 2.0–10.0 µg mL for E-110 (r = 0.9997) and for E-127 (r = 0.9999) were obtained. Commercially available tablets containing E-110 and E-127 were analysed by the proposed method and the HPLC method. Mean values and standard deviations calculated from seven determinations were 122.5 µg/tablet (RSD = 1.9) of E-110, 119.3 µg/tablet (RSD = 2.3) of E-127 for the proposed method and 124.3 µg/tablet (RSD = 0.98) of E-110, 120.9 µg/tablet (RSD = 1.2) of E-127 for the HPLC method. The statistical evaluations indicated that there was no significant difference between the mean values and precisions of the two methods at 95% confidence level (t = 1.68 and 0.24; F = 3.76 and 3.67). This method was satisfactorily used for determining synthetic mixtures of these dyes in different ratios. The avarage percentage recoveries are 105.8% and 102.8% for E-110 and E-127 respectively.
A very simple spectrophotometric method using measurements at zero-crossing wavelength is describ... more A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the food dyes, Sunset Yellow (E-110) and Quinoline Yellow (E-104). Calibration graphs are linear up to 15.0 µgml −1 of Sunset Yellow (r = 0.9998), and Quinoline Yellow (r = 0.9999). The assay procedure for E-110 and E-104 in pharmaceutical products involves the extraction of the dyes with AcOH/NaOAc buffer solution (pH = 4.5), filtration, and measurement of the second derivative absorbance values at 410.0 nm for E-104 and 533.1 nm for E-110. This method was used for determining synthetic mixtures of these dyes in different ratios and it was successfully applied to two commercial products without a previous separation step.
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996
... WASTEWATER WITH OZONE Key Words: Ozone, textile wastewater, treatment,dye. İkbal KOYUNCU*, Hü... more ... WASTEWATER WITH OZONE Key Words: Ozone, textile wastewater, treatment,dye. İkbal KOYUNCU*, Hüseyin AFŞAR* ... TEXTILE WASTEWATER TREATMENT Textile wastewatertreatment of with ozone was investigated by following the COD decrease15'. ...
A very simple spectrophotometric method using measurements at zero-crossing wavelength is describ... more A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the food dyes, Sunset Yellow (E-110) and Quinoline Yellow (E-104). Calibration graphs are linear up to 15.0 µgml −1 of Sunset Yellow (r = 0.9998), and Quinoline Yellow (r = 0.9999). The assay procedure for E-110 and E-104 in pharmaceutical products involves the extraction of the dyes with AcOH/NaOAc buffer solution (pH = 4.5), filtration, and measurement of the second derivative absorbance values at 410.0 nm for E-104 and 533.1 nm for E-110. This method was used for determining synthetic mixtures of these dyes in different ratios and it was successfully applied to two commercial products without a previous separation step.
In this investigation, titanium oxide plates were used as cathode for hydrogen production in the ... more In this investigation, titanium oxide plates were used as cathode for hydrogen production in the aqueous solutions of sulfuric acid, potassium hydroxide, acetic acid and ammonia hydroxides electrolytes separately. Gaseous hydrogen was produced at the cathode and oxygen at the anode. For this purpose, titanium plates were fabricated in acid solution by anodic oxidation. Microstructure of TiO 2 nanorod observation was conducted with scanning electron microscopy (SEM). The effects of operating conditions and the electrochemical test parameters, such as electrolytes concentration, temperature, and cell voltage were investigated. Also the performance of TiO 2 cathode was compared to zirconium oxide and graphite electrodes. The results show that the highly rated, hydrogen production performance on TiO 2 cathode has better than the other electrodes. The maximum rate of hydrogen production is by TiO 2 cathode 8.18 ml/ (h. cm 2). The cell efficiency for water electrolysis was reached 95% using titanium oxide electrode in 1.5 M H 2 SO 4 .
Rationale: Pesticides are poisonous substances or mixtures of dangerous chemicals used to prevent... more Rationale: Pesticides are poisonous substances or mixtures of dangerous chemicals used to prevent, dissuade, control, or eradicate insects, weeds, rodents, fungi, or other potentially dangerous organisms. Pesticides must be separated from complex matrices before analysis by performing the proper extraction, cleaning, and/or preconcentration processes. The QuEChERS method served as a matrix clean-up tool and the DLLME method preconcentrated the analytes for their determination at trace
Bulletin of Environmental Contamination and Toxicology, Nov 23, 2018
Antimony is known to have some adverse health effects on human health. Flame atomic absorption sp... more Antimony is known to have some adverse health effects on human health. Flame atomic absorption spectrometry (FAAS) is a widely used instrumental for the determination of antimony and other metals. However, it lacks the sensitivity to determine these metals at trace levels. This study was aimed at overcoming this setback by using hydrogen assisted T-shaped slotted quartz tube technique to preconcentrate and determine antimony by FAAS. All the system parameters were optimized to enhance the detection power of the system. Under the optimum experimental conditions, the limits of detection and quantification were found to be 0.75 and 2.49 µg L −1 , respectively with R 2 value of 0.9999. Accuracy of the developed method was validated by experimental results agreeing to the certified value of a standard reference material. Recovery studies were also carried out to determine the method's applicability to tap and mineral water samples, and the results obtained were appreciable.
This study aims to develop coating quality by using Flow Analysis (FA) technique in acid copper c... more This study aims to develop coating quality by using Flow Analysis (FA) technique in acid copper coating bath. The coating metal concentration of electrodeposition bath mixture, current density, coating time, distance between anode and cathode, temperature of bath mixture and pH are some of the factors which affect the coating quality. The coating metal concentration is the most important parameter. The metal concentration of electroplating bath solution decreases during the coating so coating quality also decreases. Bath mixture composition has been determined by analysing samples periodically according to the conventional industrial application. Much more time, effort and high financial cost are very necessary for this type of analysis. This paper represents a new method which determines the metal concentration of coating baths with flow analysis technique. The metal concentration is measured on-line with spectrophotometric technique which includes flow through cell according to the new method. This technique is very simple and the results can be taken easily. Firstly, the decrease in metal concentration is determined by the batch technique and then a sufficient amount of stock metal solution is added to the plating bath continuously by on-line system. The metal concentration of coating bath solution is kept at constant concentrations. This means that the coating metal quality does not
Background Presently, there is no validated method for stability-indicating related substances of... more Background Presently, there is no validated method for stability-indicating related substances of adenosine used in the treatment of cataracts and found in different combined eye drop products. Objective A stability-indicating related substances analytical method for adenosine used in the treatment of cataracts and found in different combined eye drop products should be developed and validated. Method A new reverse phase-HPLC method of determination for adenosine-related compounds has been developed and validated according to the International Council for Harmonisation. In this method, all impurities were easily detected for adenosine, which is found in combination with different active ingredients such as nicotinic acid and nicotinamide. The impurities obtained by a stress test were purified and their structures were characterized by mass spectroscopy (LC-QTOF-MS). Results The concentration range for linearity was evaluated as 0.06–4.27 µg/mL for adenosine, 0.15–4.27 µg/mL for uridine, 0.15–4.17 µg/mL for inosine, 0.13–4.35 µg/mL for guanosine, and 0.12–4.26 µg/mL for adenine. Good linearity was achieved for each component, and it was determined that the correlation coefficient (r) met the acceptance criterion r ≥ 0.99. The accuracy of the method was good-to-excellent recoveries at each concentration level (from LOQ to 120% of the specification limit) were achieved within the limit range of 80.0–120.0%, and RSD of recoveries was found below 10.0% for both formulations. Conclusions With this economical and simple method validated in accordance with the ICH Q2 (R1) guideline, a new method has been created for adenosine, which is suitable for routine analysis. Highlights The validated method is a very simple and suitable method for green chemistry without any pre-processing, and the structure of the impurities obtained as a result of stress studies was confirmed by LC-QTOF-MS.
Simple and fast spectrophotometric methods for the determination of the components of ternary mix... more Simple and fast spectrophotometric methods for the determination of the components of ternary mixtures of dyes have been proposed. For the simultaneous determination of Sunset Yellow (E110), Tartrazine (E102), and Ponceau4R (E124) in granulated drinks partial least square (PLS) method was applied to the spectrophotometric data in the range 400-600 nm, at 10 nm intervals. In the procedure 27 standard mixtures of three assayed compounds at three concentration levels were used. Absorbance measurements were performed in methanolic solutions. The results were compared with those obtained using a common derivative spectrophotometric procedure (zero-crossing technique). These procedures did not require any separation steps. Statistical evaluation of the method bias was performed. It was concluded that PLS method might be competitive with derivative procedure for the separation of ternary mixtures of dyes.
Metal adsorption studies are getting important and there are many functional adsorbents developed... more Metal adsorption studies are getting important and there are many functional adsorbents developed recently. Here, we report the synthesis of multifunctional PAMAM G2 (polyamidoamine) possessing methacryl, amine, hydroxyl and phosphonate groups used in free radical curing gel formulations. UV curable gel is conducted in the presence of acrylamide, bisacrylamide, and polyethylene glycol diacrylate. Adsorption study of the resulting novel sorbents (gels) are carried out with a series of metals. Through a comprehensive study, structure–property relationship of the series gels is conducted by using different amount of amine, hydroxyl, and/or phosphonate ester groups on the PAMAM G2. Selected metals are Cr3+, Fe3+, Ni2+, Cu2+, Ag+, and Cd2+ within a series of hard, intermediate, and soft ionic species. Adsorption study is carried out in pure water environment at neutral pH. Metal ions removal percentages and adsorption capacities of gel adsorbents are calculated by using atomic absorption spectroscopy. There is relationship between the overall functional groups presence in gel formulation and swelling densities for removing the metal ions. Introducing dendrimer into the gel formulation enhanced the metal ions adsorption against to Bare GEL formulation which do not possess dendrimer units. Consequently, the maximum removal efficiency has been obtained for Cr3+ and Fe3+.
In the present work, a method has been described for the determination of copper and lead by flam... more In the present work, a method has been described for the determination of copper and lead by flame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and coflotation. Purolite S-940, that is a strong cation exchanger, was used for preconcentration and separation of the trace metals as the first method. Optimum metal uptake conditions were investigated using batch systems. These optimum conditions are: pH, contact time, the initial metal concentration and the amount of resin. Using results obtained from experiments of optimum conditions, Cu and Pb in water samples which were taken from ISKI (Water Authority for Istanbul) Kagithane and ISKI Biiyilk9ekmece were enriched and determined by FAAS. The second method is a preconcentration and separation using hexamethylendithiocarbomate as a chelating agent for colloid flotation Cu and Pb from water. The influences arising from pH, nitric acid concentration, amount of analytes, and sample volume on the recoveries were assessed. Cu and Pb in water samples which were taken from ISKI Kagithane and ISKI Büyüksekmece were enriched and determined by FAAS.
An accurate, fast and simple method for determination of thallium in environmental water samples ... more An accurate, fast and simple method for determination of thallium in environmental water samples with Zeeman electrothermal atomic absorption spectrometry (ZETAAS) by previous flotation preconcentration is given. The possibility of using Co(III) dithiocarbamates as colloidal precipitate collectors for simultaneously flotation separation of Tl(I) and Tl(III) from water matrices was studied. The experiments showed that Co(HMDTC) 3 as a collector for flotation of both Tl species is far more effective than Co(HpDTC) 3. The limit of detection of Tl is 0.031 µg/l.
Two preconcentration techniques, ion exchange and fl otation, were used for the determination of ... more Two preconcentration techniques, ion exchange and fl otation, were used for the determination of zinc (Zn), nickel (Ni) and cadmium (Cd) in natural water samples. In the fi rst part of our work, the adsorption of zinc(II), nickel(II) and cadmium(II) on Lewatit TP 207 chelating resin containing iminodiacetate groups was studied at different pH values by a batch process. The effects of parameters such as amount of resin, contact time, pH and initial metal concentration on the ion exchange separation were investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions were also studied. The concentrations of metal ions were measured by batch techniques and with atomic absorption spectrometry analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir and Freundlich isotherms. The effi ciency of removal is higher for Ni and Zn than Cd ions. Here, we report the method that is applied for the sorption and separation of some toxic metals from the solutions. In the second part of our work, the fl otation technique was used for preconcentration. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC) 3 , as a fl otation collector for metals from natural waters was investigated. The fl otation method was compared with the ion exchange method. The recoveries of Zn, Cd and Ni from natural water samples were approximately 99 %. Our results showed that the two methods were very effective, but the fl otation results were higher than the ion exchange results. In the present study, a method was described for the determination of Zn, Ni and Cd by fl ame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and fl otation. Results of these two methods are compared. Analytical parameters such as precision and accuracy of methods were also studied. The equilibrium experimental results of Zn, Ni and Cd ions exchanged were fi tted by Langmuir-Freundlich adsorption isotherm models.
Two preconcentration techniques, ion exchange and fl otation, were used for the determination of ... more Two preconcentration techniques, ion exchange and fl otation, were used for the determination of zinc (Zn), nickel (Ni) and cadmium (Cd) in natural water samples. In the fi rst part of our work, the adsorption of zinc(II), nickel(II) and cadmium(II) on Lewatit TP 207 chelating resin containing iminodiacetate groups was studied at different pH values by a batch process. The effects of parameters such as amount of resin, contact time, pH and initial metal concentration on the ion exchange separation were investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions were also studied. The concentrations of metal ions were measured by batch techniques and with atomic absorption spectrometry analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Langmuir and Freundlich isotherms. The effi ciency of removal is higher for Ni and Zn than Cd ions. Here, we report the method that is applied for the sorption and separation of some toxic metals from the solutions. In the second part of our work, the fl otation technique was used for preconcentration. The ability of Co(III) hexamethylenedithiocarbamate, Co(HMDTC) 3 , as a fl otation collector for metals from natural waters was investigated. The fl otation method was compared with the ion exchange method. The recoveries of Zn, Cd and Ni from natural water samples were approximately 99 %. Our results showed that the two methods were very effective, but the fl otation results were higher than the ion exchange results. In the present study, a method was described for the determination of Zn, Ni and Cd by fl ame atomic absorption spectrometry (FAAS) after preconcentration and separation in water by ion exchange resin and fl otation. Results of these two methods are compared. Analytical parameters such as precision and accuracy of methods were also studied. The equilibrium experimental results of Zn, Ni and Cd ions exchanged were fi tted by Langmuir-Freundlich adsorption isotherm models.
Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders... more Two methods for the simultaneous determination of Sunset Yellow and Ponceau 4R in gelatin powders by first derivative spectrophotometry and by partial least-squares multivariate spectrophotometric calibration are described. These procedures do not require any separation step. These methods were applied to determine both colorants in commercial gelatin powders and the results obtained were compared. A good statistical agreement was obtained
ABSTRACT A classic analytical problem is the simultaneous determination of two or more compounds ... more ABSTRACT A classic analytical problem is the simultaneous determination of two or more compounds in the same sample without previous chemical separation. In this way derivative spectrophotometry is an anaytical technique of great utility and offers greater selectivity than normal spectrophotometry. The resolution of binary mixtures of compounds with overlapped spectra by derivative spectrophotometry is frequently made on the basis of zero-crossing measurements. A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the synthetic colorants sunset yellow (E-110) and erythrosine (E-127). The assay procedure for E-110 and E-127 in Premarin tablets involves extraction of the colorants from tablets with distilled water and measurement of first derivative absorbance values at 482.7 nm for E-127, then filtration from rough paper and measurement of D values at 526.3 nm for E-110. Linear correlations over the concentration ranges of 2.0–10.0 µg mL for E-110 (r = 0.9997) and for E-127 (r = 0.9999) were obtained. Commercially available tablets containing E-110 and E-127 were analysed by the proposed method and the HPLC method. Mean values and standard deviations calculated from seven determinations were 122.5 µg/tablet (RSD = 1.9) of E-110, 119.3 µg/tablet (RSD = 2.3) of E-127 for the proposed method and 124.3 µg/tablet (RSD = 0.98) of E-110, 120.9 µg/tablet (RSD = 1.2) of E-127 for the HPLC method. The statistical evaluations indicated that there was no significant difference between the mean values and precisions of the two methods at 95% confidence level (t = 1.68 and 0.24; F = 3.76 and 3.67). This method was satisfactorily used for determining synthetic mixtures of these dyes in different ratios. The avarage percentage recoveries are 105.8% and 102.8% for E-110 and E-127 respectively.
A very simple spectrophotometric method using measurements at zero-crossing wavelength is describ... more A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the food dyes, Sunset Yellow (E-110) and Quinoline Yellow (E-104). Calibration graphs are linear up to 15.0 µgml −1 of Sunset Yellow (r = 0.9998), and Quinoline Yellow (r = 0.9999). The assay procedure for E-110 and E-104 in pharmaceutical products involves the extraction of the dyes with AcOH/NaOAc buffer solution (pH = 4.5), filtration, and measurement of the second derivative absorbance values at 410.0 nm for E-104 and 533.1 nm for E-110. This method was used for determining synthetic mixtures of these dyes in different ratios and it was successfully applied to two commercial products without a previous separation step.
Journal of Environmental Science and Health . Part A: Environmental Science and Engineering and Toxicology, 1996
... WASTEWATER WITH OZONE Key Words: Ozone, textile wastewater, treatment,dye. İkbal KOYUNCU*, Hü... more ... WASTEWATER WITH OZONE Key Words: Ozone, textile wastewater, treatment,dye. İkbal KOYUNCU*, Hüseyin AFŞAR* ... TEXTILE WASTEWATER TREATMENT Textile wastewatertreatment of with ozone was investigated by following the COD decrease15'. ...
A very simple spectrophotometric method using measurements at zero-crossing wavelength is describ... more A very simple spectrophotometric method using measurements at zero-crossing wavelength is described for resolving binary mixtures of the food dyes, Sunset Yellow (E-110) and Quinoline Yellow (E-104). Calibration graphs are linear up to 15.0 µgml −1 of Sunset Yellow (r = 0.9998), and Quinoline Yellow (r = 0.9999). The assay procedure for E-110 and E-104 in pharmaceutical products involves the extraction of the dyes with AcOH/NaOAc buffer solution (pH = 4.5), filtration, and measurement of the second derivative absorbance values at 410.0 nm for E-104 and 533.1 nm for E-110. This method was used for determining synthetic mixtures of these dyes in different ratios and it was successfully applied to two commercial products without a previous separation step.
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