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Öğe Bacillus sp immobilized on Amberlite XAD-4 resin as a biosorbent for solid phase extraction of thorium prior to UV-vis spectrometry determination(Springer Wien, 2010) Ozdemir, Sadin; Erdogan, Sait; Kilinc, ErsinA method has been developed for the preconcentration of Th prior to its determination by UV-vis spectrophotometry after complexation with Arsenazo Ill. A column was packed with Amber lite XAD-4 resin containing immobilized Bacillus sp. as a solid phase extractant. Parameters such as pH of the solution and sample, the concentration of Th, the volume and type of eluent, flow rate and effect of matrix interference were studied. The optimum pH for the sorption of Th is 5.0, and quantitative eluation occurs with 1 mol L-1 HCl. The tolerance limits of some electrolytes were also studied. The loading capacity was determined to be 17.2 mg g(-1) The method was applied to the determination of Th in real ore sample and validated by analyzing a certified reference samples (NCS DC-73350; poplar leaves).Öğe Chemical Characteristics of Settled Particles during a Dust-Storm(Hard, 2012) Aydin, Firat; Aydin, Isil; Erdogan, Sait; Akba, Osman; Isik, Birgul; Hamamci, CandanMajor synoptic systems bring desert dust from Arabia and the Sahara to Anatolia, Turkey. A study of particulate matter (PM) associated metal content such as As, Al, Cr, Cd, Co, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Sn, and Zn, etc., has been carried out for Diyarbakir, SE Anatolia, Turkey. Results show that the PM10 levels during a dust storm were much higher than in a non-dust-storm period and that four metals (Fe, Al, Cr, Mn) were dominant in settled particles. This research does not only provide background data for air quality management, but also provides valuable information about the chemical composition of the particles.Öğe Effect of electromagnetic fields and antioxidants on the trace element content of rat teeth(Dove Medical Press Ltd, 2017) Dogan, Mehmet Sinan; Yavas, Mehmet Cihan; Yavuz, Yasemin; Erdogan, Sait; Yener, Ismail; Simsek, Ibrahim; Akkus, ZekiThe purpose of this study was to examine the possible effect of extremely low-frequency electromagnetic fields (ELF-EMFs), from a high-voltage source, on rat teeth in terms of changes in trace elements (TEs) and the effect of antioxidants (melatonin [MLT] and Ganoderma lucidum [GL]) in counteracting these effects. We used adult male Wistar albino rats with a mean weight of 250-300 g and divided the rats into eight groups. The groups were subjected to an ELF- EMF that was applied with a high- voltage line for 8 hours/day for 26 days (Groups I, II, and III) or 52 days (Groups V, VI, and VII). Groups IV and VIII were the 26- and 52- day control/sham groups, respectively. Groups II and VI were treated with GL, and Groups III and VII were treated with MLT. MLT and GL were administered daily based on the weight of the animals and appropriate standards. At the end of the study, the rats were euthanized, and their anterior teeth were extracted. The teeth were preserved in pure water before evaluating the major TEs. At the end of the study, TE concentrations (in mg/kg) were assessed in the control and test groups. Compared with Group V, statistically significant differences in the concentrations of zinc (Zn) and strontium (Sr) were found for Group VII (ELF- EMF + MLT) (P< 0.05). Therefore, ELF- EMF exposure can change the content of certain TEs in teeth and, after administering MLT and GL, the values of some of the TEs return to normal.Öğe Extremely Low-Frequency Magnetic Field Decreased Calcium, Zinc and Magnesium Levels in Costa of Rat(Humana Press Inc, 2011) Ulku, Refik; Akdag, Mehmet Zulkuf; Erdogan, Sait; Akkus, Zeki; Dasdag, SuleymanElectromagnetic field (EMF) can affect cells due to biochemical change followed by a change in level of ions trafficking through membrane. We aimed to investigate possible changes in some elements in costa of rats exposed to long-term extremely low-frequency magnetic field (ELF-MF). Rats were exposed to 100 and 500 mu T ELF-MF, which are the safety standards of public and occupational exposure for 2 h/day during 10 months. At the end of the exposure period, the samples of costa were taken from the rats exposed to ELF-MF and sham. The levels of elements were measured by using atomic absorption spectrophotometry (AAS) and ultraviolet (UV) spectrophotometry. Ca levels decreased in the ELF-500 exposure group in comparison to sham group (p < 0.05). Statistically significant decrease was found in Mg levels in the ELF-500 exposure group in comparison to sham and ELF-100 exposure groups (p < 0.05). Zn levels were found to be lower in the ELF-500 exposure group than those in the sham and ELF-100 exposure groups (p < 0.05). No significant differences were determined between groups in terms of the levels of P, Cu and Fe. In conclusion, it can be maintained that long-term ELF-MF exposure can affect the chemical structure and metabolism of bone by changing the levels of some important elements such as Ca, Zn and Mg in rats.Öğe High-Performance Liquid Chromatography Analysis and Assessment of Benzoic Acid in Yogurt, Ayran, and Cheese in Turkey(Springer, 2012) Yildiz, Aydin; Erdogan, Sait; Saydut, Abdurrahman; Hamamci, CandanAmong food sources, particular attention is paid to milk and dairy products, due to its nutritional importance. Benzoic acid is extensively used in the preservation of foods. A reliable method for the determination of benzoic acid in some dairy products, such as yogurt, ayran, and cheese using high-performance liquid chromatography and UV detection was validated. The peak of benzoic acid was measured at a wavelenght of 226 nm. Samples were purchased from supermarkets in Turkey in the period 2009-2010. All dairy product samples were produced from cow's milk. The levels of benzoic acid in cheese, yogurt, and ayran samples were in the range of 3.17 to 56.77 mg kg(-1), 8.94 to 28.30 mg kg(-1), and 1.54 to 16.57 mg L-1, respectively. The results show that benzoic acid widely occurs in milk products in Turkey at the low levels.Öğe Macro and micro element contents in fruiting bodies of wild edible mushrooms from Mugla in Southwest Anatolia, Turkey(Asian Journal Of Chemistry, 2006) Erdogan, Sait; Yilmaz-Ersela, Fadime; Merdivan, MelekThe macro (K, Na, Mg, Ca) and micro (Fc, Zn, Cu, Mn, Cd, Co, Ni) element contents in 8 different wild edible mushroom species were studied in Southwest Anatolia, Turkey. The study investigated the differences in metal accumulation in relation to species. The mean concentrations of metals in the individual species did not vary to a large extent. The tricholomataceae species in this study had higher protein values than the others. The highest mean concentration of macro elements was found for K (135 g/kg), followed by Mg (1.23 g/kg), Na (0.58 g/kg) and Ca (0.33 g/kg) in Tricholoma terreum (Schff.: Fr.) Kummer. The mean concentrations of micro elements for all species were in the following order: Fe > Zn Cu > Mn > Ni > Cd. Pb and Co were not detected in the studie > d species. The highest amount of micro elements was determined for Cd (8,83 mg/kg), Fe (268 mg/kg) and Zn (100 mg/kg) in T terreum and for Cu (53.1 mg/kg) and Mn (23.5 mg/kg) in Clitocybe alexandri (Gill.) Konr.Öğe Major and Trace Element Contamination of Short-Term Snow Cover During and After a Dust Storm and Analysis by ICP-OES(Atomic Spectroscopy Press Ltd, 2013) Akba, Osman; Kilinc, Ersin; Aydin, Isil; Erdogan, Sait; Aydin, Firat; Duz, M. Zahir; Hamamci, CandanThe levels of major and trace elements are key data for evaluating the toxicity of potential particulate matter and for identifying pollution sources. From this point of view, snow is considered an ideal matrix to observe deposition from the atmosphere due to environmental and anthropogenic activities. This work has demonstrated that major and trace element levels of Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Se, Sn, and Zn were found in snow precipitation sampled during and after a dust storm in and around Diyarbakir city, SE Anatolia, Turkey. A simple methodological approach consisting of surface snow sampling and analysis by ICP-OES provides information about the spatial distribution and temporal evolution of atmospheric precipitation. The concentrations of toxic metals were found at high levels and are therefore a threat to human health. In particular, the concentrations for Fe and Al were significantly higher than for the other elements.Öğe Methyl ester of peanut (Arachis hypogea L.) seed oil as a potential feedstock for biodiesel production(Pergamon-Elsevier Science Ltd, 2009) Kaya, Canan; Hamamci, Candan; Baysal, Akin; Akba, Osman; Erdogan, Sait; Saydut, AbdurrahmanThe peanut (Arachis hypogea L.) seed oil was extracted from the seeds of the peanut that grows in SE Anatolia of Turkey. Oil was obtained in 50 wt/wt.%, by solvent extraction. Peanut (A. hypogea L) seed oil was investigated as an alternative feedstock for the production of a biodiesel fuel. Biodiesel was prepared from peanut by transesterification of the crude oil with methanol in the presence of NaOH as catalyst. A maximum oil to ester conversion was 89%. The viscosity of biodiesel oil is nearer to that of petroleum diesel and the calorific value is about 6% less than that of diesel. Peanut seed oil have about 8.3% less heating value than that of diesel oil due to the oxygen content in their molecules. The quality of biodiesel is most important for engine part of view and various standards have been specified to check the quality. The important properties of peanut oil and its methyl ester (biodiesel) such as density, kinematic viscosity, flash point, iodine number, neutralization number, pour point, cloud point, cetane number are found out and compared to those of no, 2 petroleum diesel, ASTM and EN biodiesel standards. The comparison shows that the methyl ester has relatively closer fuel properties to diesel than that of raw peanut seed oil. (C) 2008 Elsevier Ltd. All rights reserved.Öğe Microwave Digestion Followed by ICP-OES for the Determination of Al, Cd, Cr, Cu, Fe, Ni, Pb, and Sn in Maize(Atomic Spectroscopy Press Ltd, 2012) Duz, M. Zahir; Celik, K. Serdar; Aydin, Isil; Erdogan, Sait; Aydin, Firat; Hamamci, CandanMaize (Zea mays L.) is currently the most widely grown crop in the world and is used not only for food and animal feed but also to produce industrial starches, biodiesel, ethanol, and oils. The present work reports the results obtained by the proposed method for the determination of metals (M, Cd, Cr, Cu, Fe, Ni, Pb and Sn) in maize by ICP-OES, using digestion with an oxidant mixture in a closed-vessel microwave oven. The results in the maize samples (minimum-maximum in mg/kg) were: Al 6.678-7.051, Sn 2.092-3.977, Cr 0.394-0.423, Cu 21.56-24.78, Fe 93.37-102.86, Ni 1.679-1.877 and Pb 0.375-0.392. The concentration of Cd was below the detection limit (< 0.03 mg/kg). The certified reference material, CRM NIST1573a Tomato Leaves, was used in order to verify the accuracy of the microwave digestion method. The results of this study were in good agreement with the certified values.Öğe A New Preconcentration Method for the Determination of Pb and Ni in Real Samples by Using Amberlite XAD-16 Functionalized With 1,6-bis(2-carboy aldehyde phenoxy)butane(Atomic Spectroscopy Press Ltd, 2019) Oral, Elf Varhan; Erdogan, Sait; Temel, Hamdi; Ziyadanogullari, Berrin; Ziyadanogullari, RecepIn this study, a steady chelating resin matrix was formed by tying 1,6-bis(2-carboxy aldehyde phenoxy) butane to Amberlite XAD-16 resin by a -C=N- group. This synthesized adsorbent was placed into a minicolumn to separate and preconcentrate the lead and nickel ions before their determination by flame atomic absorption spectrometry (PARS). The effects of many parameters on the preconcentration method were examined. The optimal pH value for the quantitative absorption of lead and nickel was pH 5.0. The percentage of recovery for lead and nickel was 99 +/- 1.15% and 100 +/- 2.70%, respectively. The detection limits of lead and nickel utilizing FAAS (3s, N=20) were 1.47 and 1.16 mu g/L, respectively. The effects of some matrix components on the recovery were analyzed. The suggested method was utilizied to determine lead and nickel in real water samples obtained from the River Tigris in Turkey, as well as in automobile exhaust particles, Romaine letnice, and parsley. The accuracy of the proposed method was verified by using the standard addition method and the standard reference material NCS-DC 73350 Poplar Leaves.Öğe Preconcentration of cadmium and nickel using the bioadsorbent Geobacillus thermoleovorans subsp stromboliensis immobilized on Amberlite XAD-4(Springer Wien, 2010) Ozdemir, Sadin; Gul-Guven, Reyhan; Kilinc, Ersin; Dogru, Mehmet; Erdogan, SaitCadmium and nickel ions have been preconcentrated on Geobacillus thermoleovorans subsp. stromboliensis, immobilized on Amberlite XAD-4, and were determined by flame atomic absorption spectrometry (FAAS). Parameters such as pH, amount of adsorbent, eluent type and volume, flow rate of solution and the matrix interference effect on retention have been studied, and extraction conditions were optimized. Elution of Cd(II) and Ni(II) from minicolumns was carried out with 1.0 M hydrochloric acid or nitric acid with recoveries from 97 to 100%. The sorption capacity is 0.0373 and 0.0557 mmol g(-1) for Cd(II) and Ni(II), respectively. The detection limits were 0.24 mu g L-1 for cadmium and 0.3 mu g L-1 for nickel. The relative standard deviations of the procedure were below 10%. The procedure was validated by analyzing certified reference materials and applied to the determination of Cd(II) and Ni(II) in natural water and food samples.Öğe Process optimization for production of biodiesel from hazelnut oil, sunflower oil and their hybrid feedstock(Elsevier Sci Ltd, 2016) Saydut, Abdurrahman; Erdogan, Sait; Kafadar, Aylin Beycar; Kaya, Canan; Aydin, Firat; Hamamci, CandanThe most important constituent needed for biodiesel development is the feedstock. As the availability of feedstock is limited, the possibility of using the hybrid feedstock has been explored. Biodiesel has been synthesized from hazelnut (Corylus avellana L.) kernel oil, sunflower (Helianthus annuus L.) oil and hybrid (hazelnut and sunflower) (50: 50 v/v) feedstocks. Ester yield of vegetable oil to fatty acid methyl esters (FAME) was found to be 97.5%, 97.3% and 97.9% for hazelnut, sunflower and hybrid feedstocks respectively. The reaction parameters were used to be 6: 1 (methanol to oil) molar ratio, KOH (0.7%), at 60 +/- 0.5 degrees C for 2 h during alkali esterification for the three feedstocks. High yield from hybrid feedstock during transesterification reaction clearly indicated that the reaction was not selective for any particular oil. The obtained results important in that in case of scarcity of feedstock both oils could be mixed as well to maintain the constant supply of the feedstock in the perspective of industrial production of biodiesel. (C) 2016 Elsevier Ltd. All rights reserved.Öğe Relationship between wintertime atmospheric particulate matter and meteorological conditions in Diyarbakir (Turkey)(Asian Journal Of Chemistry, 2007) Erdogan, Sait; Baysal, Akin; Akba, Osman; Merdivan, Melek; Hamamci, CandanThis paper reported the changes in pollution concentration in Diyarbakir, South east region of Turkey in the winter half of the year from 1986 to 2004 and describes the relationships with meteorology. Particulate matter (PM),, is used as the example Pollutant. Decrease in air pollution since 1994 was observed due to air pollution control and management strategies. The winters of 1988-1989, 1989-1990, 1990-1991, 1991-1992 and 1992-1993 were especially harsh in the number of pollution episodes. Linear regression results show that relative humidity and temperature provide the relationship with PM10 concentration.Öğe Removal of sulfur and ash from coal using molten caustic leaching, a case study from Hazro fields, Turkey(Sage Publications Inc, 2009) Duz, M. Zahir; Saydut, Abdurrahman; Erdogan, Sait; Hamamci, CandanMolten caustic leaching process is effective in reducing significant amount of ash derived from minerals, pyritic sulfur, and organic sulfur from coal. The effect of leaching coal samples from Hazro fields, situated in Southeast Anatolia region of Turkey with molten sodium hydroxide as well as followed by mild acid on demineralization and desulfurization was investigated. The effects of alkali/coal ratio, time, and temperature on the leaching efficiency were detailed and the experimental results are presented here. Chemical demineralization and desulfurization of coal samples using molten sodium hydroxide was investigated in the temperature range of 200-400 degrees C. The percentage of demineralization and desulfurization increased with the increase in alkali/coal ratio. The removal of total sulfur and ash increases with increasing leaching temperature and time. As a result of MCL. ash content of Hazro coal was reduced from 18.31 to 6.77 %, and 70% of combustible was recovered. Total sulfur and volatile matter content was reduced from 7.54 to 1.01% and from 47.80 to 12.41%, respectively. Most of the inorganic sulfur and a significant portion of the organic sulfur were removed.Öğe Simultaneous Determination of Transition Metals in Hazelnuts (Corylus avellana L.) by ICP-OES(Atomic Spectroscopy Press Ltd, 2014) Celik, K. Serdar; Aydin, Firat; Duz, M. Zahir; Aydin, Isil; Erdogan, Sait; Akba, Osman; Hamamci, CandanHeavy metal concentrations in foods are of interest because of their essential or toxic nature. The present work reports the results obtained for the simultaneous determination of essential and/or toxic metals (Cd, Co, Cr, Cu, Fe, Ni, Pb, Zn) in 24 hazelnut samples by inductively coupled plasma optical emission spectrometry (ICP-OES) after sample digestion using a diluted oxidant mixture in a closed-vessel microwave system. The obtained results (mean in mg/kg) were: Co 1.15, Cr 1.92, Cu 17.96, Fe 489, Ni 4.76, and Zn 85. The concentrations of Cd and Pb were below the detection limits and are below the daily intake recommended by the international organizations (WHO). Therefore, it can be stated that hazelnuts are safe for public consumption. The macro and micro nutrient ranges in hazelnut (Corylus avellana L.) did not exceed the dietary reference intake (DRI).Öğe Simultaneous Multielement Determination of Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn, and Zn in Bulgur Wheat by ICP-OES(Atomic Spectroscopy Press Ltd, 2015) Erdogan, Sait; Aydin, Isil; Duz, M. Zahir; Aydin, Firat; Celik, K. Serdar; Akba, Osman; Hamamci, CandanBulgur is one of the oldest cereal-based foods. This study explains the simultaneous determination by the proposed method for toxic elements such as Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Sn, and Zn in bulgur by ICP-OES following digestion in a closed-vessel microwave system. The ICP-OES method is used because it is precise, rapid, simple, and accurate for the determination of 12 metals. The technique can be considered useful for the routine analysis of multi-elements in cereals as well as for quality control purposes. The obtained results in the bulgur samples (mean in mg kg(-1)) were: Al 0.81, Cr 0.19, Cu 3.80, Fe 26.75, Mn 13.60, Ni 0.25, Pb 0.23, Sn 0.17, and Zn 14.30. The concentrations of As, Cd, and Hg were below the detection limits. A certified reference material was used to verify the accuracy of the studied method. The results were in good agreement with the certified values. The toxic metal concentrations are low and the obtained values are suitable for daily intake. The macro and micro nutrient ranges in bulgar wheat did not exceed the dietary reference intake (DRI). The bulgur produced in Turkey has very low levels of toxic metals, is safe for human consumption, and is a highly nutritional and healthy food source. Bulgur wheat is, therefore, safe for public consumption.Öğe The use of Bacillus subtilis immobilized on Amberlite XAD-4 as a new biosorbent in trace metal determination(Elsevier Science Bv, 2007) Dogru, Mehmet; Gul-Guven, Reyhan; Erdogan, SaitThe present work proposes the use of Bacillus subtilis immobilized on Amberlite XAD-4 as new biosorbent in trace metal determination. The procedure is based on the biosorption of Cu and Cd ions on a column of Amberlite XAD-4 resin loaded with dried, dead bacterial components prior to their determination by flame AAS. Various parameters such as pH, amount of adsorbent, eluent type and volume, flow rate of solution and matrix interference effect on the retention of the metal ions have been studied. The optimum pH values of quantitative sorption for Cu and Cd were found to be 7.0 and 7.5, respectively. These metal ions can be desorbed with 1 M HCl (recovery, 96-100%). The,sorption capacity of the resin was 0.0297 and 0.035 mmol g(-1) for Cu(2+) and Cd(2+), respectively. The tolerance limit of some electrolytes were also studied. This procedure was applied to Cu(2+) and Cd(2+) determination in aqueous solutions, including river and well water systems. In order to evaluate the accuracy of the proposed procedure, the certified reference materials, NRCC-SLRS-4 Riverine water and LGC7162 Strawberry leaves were analyzed. (C) 2007 Elsevier B.V. All rights reserved.
