In this work, dry deposition of metals is investigated in an urban area / city of Ankara using snow as a surrogate surface. Two sampling campaigns were conducted to determine dry deposited amount of 13 species namely / H+, Na, K, Al, Mg, Fe, V, Cd, Cr, Cu, Pb, Zn, Ni. First sampling was performed after a major snow fall in Ankara in January 2001, from 4 points according to a predetermined sampling procedure in order to assess background composition of snow. After 12 days, snow samples were collected from 54 points. All samples are filtered, digested and divided into two aliquots in order to investigate soluble and insoluble fractions separately. Temporal changes of snow showed that snow is a good surrogate surface for dry deposition of metals and provide multifunctional informative data. Pollution maps of the city are drawn using Mapinfo software to investigate spatial pollution distributions. Factor analysis are applied and five main factors for these elements are found, indicating three main sources as traffic, soil and combustion. Enrichment factor calculations showed that Ni, Ca, Pb, Zn, Ni, Cu and Cd are highly enriched pointing out the anthropogenic sources affecting the city atmosphere drastically.

In sugar industry, determination of invert sugars (fructose and glucose) provides information about the quality, process control and characteristics of the produced fructose and glucose syrups. Determination of invert sugar is also important for wine industries. In wine process, fructose and glucose are converted to ethanol by fermentation and the type of wine is designated by the amount of invert sugar remained. Fast and reliable invert sugar detection techniques are required to check the quality of wine throughout the fermentation process. Cathecholamines (eg. dopamine and epinephrine) are diol containing compounds which play important roles in higher animals&rsquo / physicomotor activities, learning, sleeping, memory and immune system. They also affect brain functions. Inbalances in dopamine level in brain result in a number of psychiatric disorders, particularly schizophrenia and Parkinson disease. Catecholamines are present in relatively high amounts in drugs. Many efforts have been made to develop analytical procedures for their rapid, simple and accurate determination. For these reasons, catecholamine quantification is important in the field of pharmacy and medicine. Boronic acids interact with 1,2 or 1,3-diol containing compounds, such as fructose, glucose and dopamine, rapidly and reversibly. Hence, boronic acids are used as the recognition moeity in the construction of photoinduced electron transfer (PET) fluorophores specific for saccharides and catecholamines. In this study, a flow injection analysis system has been developed for the rapid and selective recognition of fructose and glucose in wine and in commercial sugar syrups / dopamine and epinephrine in pharmaceutical injections by using dansylaminophenyl boronic acid (DAPB) which is a fluorescent PET molecule.

Narcotic and psychotropic substances are all chemicals that affect a person&rsquo / s mental activities, perceptual abilities, behavior and level of consciousness / they may cause physical and/or psychological dependence. For determination of narcotic and psychotropic substances, chromatographic techniques are usually preferred which are aimed to identify the target chemicals and require several extraction steps. In this study, an Infrared Spectrometric method has been developed for qualitative determination of most widely encountered substances (morphine, heroin, cocaine, MDMA (3,4-methylenedioxymethamhetamine) and amphetamine) and additives (caffeine, paracetamol and lactose). Standard reference materials and illicit samples have been analyzed in powdered form by using Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR) technique. In the first part, a spectral FTIR database was constituted from the standard references. Illicit samples containing drugs and additives in varying percentages were analyzed using the same method and their database forecast results were compared with results from Gas Chromatography and High Pressure Liquid Chromatography. In the second part of the study, the possibility of finding a similarity between two samples just by comparing their spectra was investigated. For this purpose, all illicit sample spectra were collected in a new database, and then randomly selected samples were searched using this database. Most of the search attempts resulted in a correct match. Consequently, it has been observed that FTIR-ATR can be used as a priory detection step for classification studies / moreover with this technique pre-determination of narcotic and psychotropic substances can be done simply and rapidly.

ABSTRACT PRECONCENTRATION OF SOME PRECIOUS METALS USING DEBT IMPREGNATED RESIN Refiker, H&uuml / rm&uuml / s M. Sc., Department of Chemistry Supervisor: Prof. Dr. R. Sezer Ayg&uuml / n Co-supervisor: Assoc. Prof. Dr. Melek Merdivan August 2005, 107 pages In this thesis, trace amounts of gold and silver have been determined by flame absorption spectrometry (FAAS) after preconcentration by N,N-diethyl-N&#039 / -benzoylthiourea (DEBT) impregnated resin (Amberlite XAD-16). In the first part of the thesis, sorption behaviours of gold and silver with DEBT impregnated resin under optimized conditions / stirring time, pH, desorption of metals and metal ion capacities of the resin have been studied in batch process. Metal ion capacity of resin is calculated as 0.17 mmol/g resin and 0.104 mmol/g resin for silver and for gold, respectively. In the second part of the thesis, preconcentration of gold and silver was tried by DEBT impregnated resin using column process under optimized conditions / pH, flow rate and volume of sample solution, nature of eluent, flow rate and volume of eluent However, due to partial leaching of DEBT by time, no satisfactory and reproducible results could be obtained. In the final part of the study, metal chelates prepared in aqueous solutions were passed through the column under optimized conditions and satisfactory sorption-desorption and selective preconcentration could be achieved. Under optimized conditions, silver and gold ions at the concentrations of 0.05 &amp / #61549 / g/mL and 0.015 &amp / #61549 / g/mL with preconcentration factors of 7.7 and 6.7, respectively could be determined by FAAS. The proposed method is highly selective without the need for any interference elimination process. Keywords: Precious metals, Solid-phase extraction, DEBT, Amberlite XAD-16

Increasing concern about the pollution of environment by inorganic and organic chemicals arising from naturally occurring ecological events and industrial processes has created a need for the search of new techniques in the removal of these contaminants. One of the natural material that can be used in such processes is clay. Clay minerals have large surface areas and high cation exchange capacities which enables them to be modified by cationic surfactants. The material prepared, often called as &amp / #8216 / organoclay&amp / #8217 / , can be used to remove hydrophobic organic and anionic contaminants from polluted water. Among the anionic contaminants, oxyanions such as nitrate, chromate are detrimental to human life and environment even at &micro / g/L- mg/L levels. Application of organoclays for their removal from polluted water appears as one of the practical and rather cheap solution. In this study, a local clay from Ankara-Kalecik (Han&ccedil / ili Bentonite) was modified by hexadecyltrimethylammonium bromide (HDTMA-Br) to a level of twice of its cation exchange capacity. This process alters the negatively charged surface of the clay into a positively charged one, providing sites for the removal of anionic contaminants. In this study, the degree of HDTMA+ uptake by the clay within a period of eight hours is found to be 97% of the initial amount added. In desorption studies it was revealed that only about 1% of the sorbed HTDMA+ was leached in a seven days of water-organoclay interaction revealing a rather stable organoclay structure in aqeous media. Sorption experiments with nitrate, borate, and chromate solutions were performed in order to determine the anion sorption capacity of the organoclays prepared. It turns out that while untreated clay has insignificant capacity, the modified clay can remove considerable amount of nitrate and chromate ions from aqeous solutions. While the nitrate sorption was increased about eleven fold, change in chromate sorption was reached to a level of twenty fold compared to that of the untreated clay. Sorption data for nitrate and chromate are both well described by the Langmuir isotherms. No significant change was observed in case of borate-organoclay interaction. Desorption of nitrate and chromate ions from organoclay surface were also investigated. Sorption of these oxyanions were found to be almost irreversible in aqeous media. The results imply that a properly prepared organoclay can be used for the removal of oxyanions, such as nitrate and chromate from polluted water systems.

ABSTRACT EVALUATION OF METAL CONCENTRATIONS IN GROUNDWATER NEARBY SOMA COAL FIRED POWER PLANT Giuma Sasi M.S., Department of Chmistry Supervisor: Prof. Dr. Semra G. Tuncel December 2005, 95 Pages In this work, metal pollution in groundwater near by Soma coal-fired power plant was invistigated. Coal combustion results in huge amounts of bottom ash from which metals can originate and migrate to groundwater and pollute it. Forty groundwater samples were collected from water wells in an area near by the power plant to determine 14 metals namely / Na, Ca, K, Mg, Al, Ba, Fe, Zn, Cu, Pb, Cr, Cd, Ni and V. Samples were collected in polyethylene bottles, the pH of the water was measured. Then, the samples were acidified and stored to be analyzed. FAAS, FAES, GFAAS and ICP-AES were used to determine the elements. The results were compared with the WHO, the Turkish and EC guidelines for drinking water quality. Fe concentrations in 12 wells were higher the three guidelines. Zn concentrations in 5 wells were higher than the EC guidelines, but not higher than the Turkish guidelines. Pb concentrations was less than all guilelines but it was relatively high in 8 wells. The other anthropogenic elements were lower than all guidelines but these metals tend to accumulate and they will exceed the guildlines overtime. Enrichment factor calculations showed that the anthropogenic elements were enriched in the regions close to the ash piles pointing out that the ash piles are the main source of these elements. Factor analysis was applied and four main factors of the determined metals were found indicating that the power plant and the ash piles are the main source for the anthropogenic elements.

The interaction between nanoscience and biomedicine is one of the important developing areas of modern science. The usage of functional nanoparticles with biological molecules provides sensitive and selective detection, labeling and sensing of biomolecules. Until today, several novel types of tagging materials have been used in bioassays, such as plasmon-resonant particles, quantum dots (QDs), and metal nanoshells. However, nowadays, Surface enhanced raman scattering (SERS) tags have been attracting considerable attention as a tagging system. SERS-tags provide high signal enhancement, and they enable multiplex detection of biomolecules due to high specificity. This thesis is focused on the designing proper SERS nanotags for DNA studies. SERS nano-tags are nanostructures consisting of core nanoparticle generally silver, Raman reporter molecule for labeling, and shell to make surface modifications and to prevent deterioration arising from environmental impact. Based on this information, silver core synthesized by thermal decomposition and chemical reduction methods. Thermal decomposition method provides synthesis of silver nanoparticles in hydrophobic medium, resulting in proper silica coating by reverse microemulsion method. On the other hand, silver nanoparticles sythesized by chemical reduction method exhibit hydrophilic property. Due to capping reagents, negatively charged silver nanoparticles could easily attach with positively charged Raman dye which is brilliant cresyl blue (BCB). After addition of Raman active molecule, silica coating process was done by using modified St&ouml / ber method. The resulting particles were characterized by Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) ,UV-vis Spectrometry (UV-vis) and Surface-Enhanced Raman Spectroscopy (SERS). In recent years, DNA detection has gained importance for cancer and disease diagnosis and the detection of harmful microorganisms in food and drink. In this study, gene sequences were detected via SERS. For this, probe sequences were labelled with Raman reporter molecule, BCB,and SERS nano-tags and were called as SERGen probes. Then, after hybridization of DNA targets to complementary probe sequences onto gold substrate, SERS peak was followed.

In this study, agitation of solutions using different impeller and tank geometry were investigated experimentally in terms of hydrodynamics, macromixing time and aeration characteristics. In the first set of experiments a cylindrical vessel equipped with two types of hydrofoil and a hyperboloid impeller or their combinations were used. Vessel and impeller diameters and water level were 300, 100 and 300 mm, respectively. At the same specific power consumption, 163 W/m3, the so called hydrofoil 1 impeller provided the shortest mixing time at 7.8 s. At the top hydrofoil 1 impeller submergence of 100 mm, the hyperboloid impeller combination of it was the most efficient by a mixing time of 10.0 s at 163 W/m3. Ultrasound Doppler velocimetry and the lightsheet experiments showed that the hydrofoil 1, hydrofoil 2 impellers and the stated impeller combination provided a complete circulation all over the tank. Macromixing measurements were performed in square vessel for Generation 5 low and high rib and Generation 6 hyperboloid impellers. Vessel length, impeller diameters and water level were 900, 300 and 450 mm, respectively. At the same specific power consumption, 88.4 W/m3, Generation 6 mixer provided the lowest mixing time at 80.5 s. Aeration experiments were performed in square tank for Generation 5 low rib and Generation 6 hyperboloid impellers equipped with additional blades. With increasing flow number, the differences between the performances at different rotational speeds became smaller for each type of mixer. At similar conditions the transferred oxygen amount of Generation 6 impeller was about 20% better.

Trace element composition of archaeological artifacts is commonly used for provenance studies. Limestone has generally studied by geologists and there are a few researches done by various archaeological sciences. Although it is a common material for buildings and sculpture it is been thought that limestone used had not imported like marbles. Limestone figurines from Dat&ccedil / a/Emecik excavations are classified as Cypriote type, which was very popular through 6th century B.C. in the Mediterranean region. Since this type of figurines was found at Emecik numerously to determine its provenance was an important problem. Emecik figurines were examined for their some major, trace elements and REE compositions and results were compared with geological samples which were taken from a near by quarry. Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES), Inductively Coupled Plasma-Mass Spectrometry (ICPMS) have been used for analysis. The methods have been optimized by using standard reference material NIST 1d, NCS DC 73306, and IGS40.

As compared with the concentration in sample when the detection limit of analyte is low, a preconcentration method can be used. In this study, cloud point extraction (CPE) was used as the preconcentration method. The aqueous solutions of nonionic and zwitterionic surfactant materials become cloudy when its temperature reaches the cloud point temperature and analyte collapses with surface active material. The volume of surfactant rich phase is much smaller than the solution volume and therefore a way high preconcentration factor was obtained. For the cloud point extraction of selenite, a fluorimetric ligand, 2,3-diminonaphthalene (DAN) was used and the hydrophobic Se(IV)-DAN complex formed (4,5-benzopiazselenol) was extracted with Triton X-114. The effects of pH, complexation period, reaction temperature, DAN concentration and surfactant concentration on the extraction efficiency were investigated. The extraction efficiency at the optimized conditions was 98 percent. Spectrofluorimetric determination of selenium was performed at excitation and emission wavelegths of 379 nm and 582 nm, respectively. The detection limit, established as 3s /slope where s is the standard deviation of 9 measurements of 0.020 mg/L Se (IV)-DAN complex after 10 fold preconcentration was 3.7 &micro / g/L Se. By using solid surface fluorescence measurements detection limit could be reduced down to 1.2 &micro / g/L. The obtained detection limits (3.7 and 1.2 &micro / g/L) were sufficiently low for detecting selenite in diverse samples. The accuracy of the method was confirmed by the analysis of trace elements in waste water Standard reference material (EnviroMAT- Waste Water LOW EU-L-1). The interference effects of some anions and cations were also tested.