Isil Aydin

A sequential extraction to determine the distribution of phosphorus in the seawater and marine surface sediment

The distribution of phosphorus species among environmental compartments (e.g., between water and sediment), significantly affects the bioavailability of these species to organisms. The eastern Mediterranean Sea is one of the most extreme oligotrophic oceanic regions on earth in terms of nutrient concentrations and primary productivity. The paper presents the results of inorganic and organic forms in surface sediment and seawater from NE Mediterranean Sea (Burclar Bay, Erdemli, South Anatolia of Turkey) in May 2007. Speciation of phosphorus in seawater and surface sediment using inductively coupled plasma-atomic emission spectrometer (ICP-AES) has been reported here. The method is based on sequential extractions of the seawater and sediment each releasing four forms of inorganic phosphorus: loosely sorbed phosphorus, phosphorus bound to aluminium (P-Al), phosphorus bound to iron (P-Fe) and phosphorus bound to calcium (P-Ca). The most abundant form of inorganic phosphorus in the seawater and surface sediment is calcium-bound phosphorus. Relative abundances of the remaining phosphorus forms in sediment follow the order: P-Al>P-Fe>loosely bound-P and in seawater follow the order P-Fe>P-Al>loosely bound-P.

Aflatoxin species: their health effects and determination methods in different foodstuffs

AbstractCarcinogenic and mutagenic properties of aflatoxin species are known in literature. Their intake over a long time period might be health-dangerous for human even at trace levels. It is well known that different foodstuffs can be contaminated by aflatoxin species through growing and storage. Due to the serious health effects, sensitive determination of aflatoxin species in any matrices related with the human being is very crucial at trace levels. In literature, there are sensitive techniques to analyze the different samples for the contents of their aflatoxin species. Each technique has some advantages and disadvantages over the other techniques. This review aims to summarize the different health effects of aflatoxin species, development of analytical techniques and applications of developed techniques in a variety of matrices.

From mg/kg to pg/kg Levels: A Story of Trace Element Determination: A Review

Abstract Determination of the trace elements in a variety of environmental samples is of great importance. Most elements, including iron, calcium, and selenium, are crucial for the regulation of human mechanisms, and many others, like lead and cadmium, are toxic even at trace levels. Some elements, like selenium, have a narrow margin of safety. Hence, determination of elements at trace levels is crucial in any matrix related to humans. Trace element determination requires sufficiently sensitive procedures to monitor trace levels. This review aims to highlight not only the development in instrumentation for ultratrace element determination in variety of matrices but the application of developed techniques. Advantages and disadvantages of the techniques are also discussed.

Synthesis, spectroscopic and thermodynamic studies of new transition metal complexes with N,N′-bis(2-hydroxynaphthalin-1-carbaldehydene)-1,2-bis(m-aminophenoxy)ethane and their determination by spectrophotometric methods

A novel tetradentate N2O2-type Schiff base, synthesized from 1,2-bis(m-aminophenoxy)ethane and 2-hydroxynaphthalin-1-carbaldehyde, forms stable complexes with transition metal ions such as Cu(II), VO(IV) and Zn(II) in DMF. Microanalytical data, elemental analysis, magnetic measurements, UV, visible and IR spectra as well as conductance measurements were used to confirm the structures. The stability constants of these complexes in 60% (v/v) DMF–water were determined at different ionic strengths (0.07, 0.13, 0.2 M) and at different temperatures (45, 50, 55, 60 ± 0.1°C) using a spectrophotometric method. From these constants, thermodynamic stability constants and thermodynamic parameters (ΔG 0, ΔH 0, ΔS 0) were calculated. The values of enthalpy change are negative for all systems. The acid dissociation constant of the ligand, investigated in 60% (v/v) DMF–water, has also been calculated at different temperatures.

Desulfurization and Demineralization of Asphaltite Using Combination of Froth Flotation and Aqueous Caustic Leaching

The mineral matter and sulfur, which are present in varying amounts in asphaltites, are a major problem in utilization of asphaltites as a fuel. The effect of leaching asphaltites from Sirnak and Silopi, SE Anatolia, Turkey, with froth flotation following aqueous sodium hydroxide on desulfurization and deashing was investigated. Froth flotation reduced the ash content of asphaltite by 35.8 % and 35.3 %, pyritic sulfur 22.55 % and 8.7 % (wt %) and its volatile matter content by 28.9 % and 28.9 %. The asphaltite flotation yield was 79.1 % and 85.3 %. Never organic sulfur could be removed by froth flotation. The asphaltite concentration obtained from flotation was leached using aqueous sodium hydroxide and its organic sulfur content was reduced by 60.8% and 61.9 %. Hence using combination of the two methods, the total sulfur, ash and volatile matter contents was reduced by 76.4% and 71.4 %, 38.1 % and 38.3 %, 44.1 % and 47.2 %, respectively.

Synthesis, spectral studies, and determination of stability constants and thermodynamic parameters for some aromatic diamine transition-metal complexes

The Cu(II) and Zn(II) complexes of aromatic bidentate diamines were prepared and characterized by different analytical and spectral methods. Thermodynamic parameters of complexes of Cu(II) and Zn(II) cations with 1,3-bis(p-aminophenoxy)propane were determined in 60 vol. % DMF-H2O at various ionic strengths (0.07, 0.13, 0.2 M NaNO3) and different temperatures (45, 50, 55, 60 ± 0.1°C) using a spectrophotometric method. The NaNO3 solution was used to maintain the ionic strength. The stability constants show an inverse relationship with ionic strengths. The thermodynamic parameters of 60 vol. % DMF-H2O (ΔG°, ΔH°, ΔS°) based on these formation constants were determined.

Recovery of Uranium, Nickel, Molybdenum, and Vanadium from Floated Asphaltite Ash

ABSTRACT In this study, asphaltite ash obtained from asphaltite was sulfurized under an autoclave condition, and then this sample was floated by two different xanthates. The amount of uranium, nickel, molybdenum, and vanadium in the asphaltite ash was concentrated approximately 12 times. Uranium, nickel, molybdenum, and vanadium in the concentrated samples were separated in the following stages: first the concentrate was leached with different concentrations of (NH4)2CO3 to recover uranium and aluminium; in the second stage, the remaining sample was roasted with treated pyrite at 700°C and leached by water to obtain soluble nickel compounds; in the third stage, the remaining sample was leached with 15 M H2SO4 to solublise molybdenum, titanium, and iron compounds. A solid sample containing vanadium compounds was removed from a solution containing molybdenum, titanium, and iron compounds. This solution was extracted with alamine 336 to separate molybdenum from titanium and iron.

Elemental Composition of Red Wines in Southeast Turkey

Deg I rmencI Karatas D., Aydin F., Aydin I., Karatas H. (2015): Elemental composition of red wines in Southeast Turkey. Czech J. Food Sci., 33: 228–236. Mineral profiles of wines and soil extracts were analysed in the five most popular international wines (Cabernet Sauvi gnon, Syrah, Merlot, Cot, and Tannat) and national Bogazkere, which is one of the highest-quality grapevine varieties grown in Turkey. We carried out study to establish the mineral and metal concentrations in wines from Southeast Anatolia of Turkey. The ICP-OES method was used for accurate determination of concentrations of 12 elements in cluding Ca, Cd, Co, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, and Zn. The high levels of iron, potassium, sodium, and calcium were observed in the wine samples analysed. Major elements were also abundantly found in the soil samples. Minor element contents of wine samples were compatible with results other researches. The amount of metal content in wine is an important issue. A remarkable finding of the study was that heavy metals like Pb (found below acceptable limits only in three samples), Co, and Cd were not detected. The results obtained did not exceed the maximum acceptable limits established by the Office International de la Vigne et du Vin. Our results showed that the mineral compositions of wine and soils were interrelated. The analysis of the soil samples taken from the vineyard locations showed similar results for highest composition of major minerals. The characteristics of the wines produced in the Southeast Region of Turkey were analysed for the first time.

Removal of cadmium from aqueous solution by a soil containing magnesite

Removal of Cd (II) from aqueous solution by a soil containing magnesite and thermal activated soil containing magnesite was investigated. Maximum activation temperature was determined at 700°C for 2 h and maximum adsorption capacities were determined as 4.20 mg/g for natural magnesite, 38.91 mg/g for thermal activated magnesite at 25°C respectively. Equilibrium contact time of cadmium was determined for 2 h. Adsorption of Cd (II) on soil containing magnesite conforms to Langmuirs isotherm.

Molybdenum Speciation in Coal Bottom Ash Using a Sequential Extraction Procedure and Determination by FAAS

Coal bottom ash contains many elements that exist in different forms, which may change throughout the coal combustion process. This study presents the concentration and speciation of molybdenum in bottom ash of coal. Determination of total molybdenum was performed by two-stage microwave-acid digestion followed by flame atomic absorption spectrometry. A sequential extraction process to speciation of molybdenum from coal bottom ash was investigated. The most abundant form of molybdenum in samples is sulfide fraction of molybdenum. Relative abundances of the remaining fractions follow the order: Residual > Reduciple > Oxidizable > Exchangeable > Carbonate > Water soluble.