Selehattin Yilmaz

Characterization of Heavy Metal Fractions in Agricultural Soils by Sequential Extraction Procedure: The Relationship Between Soil Properties and Heavy Metal Fractions

The present research was conducted to determine heavy metals in agricultural soils from Çanakkale, Turkey, using a sequential extraction procedure (acid soluble, reducible, oxidizable, and residual) as proposed by the Community Bureau of Reference (BCR) of the European Commission. Soil samples were taken from 12 different cultivated sites and analyzed for Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentrations. The results revealed an order of Mn > Cd > Pb > Co > Ni > Cu > Zn > Cr for the heavy metals based on the sum of the first three fractions (acid soluble + reducible + oxidizable). The relationships between soil properties and each metal fraction were identified through Pearsonss correlation analysis. Hierarchical cluster analysis was performed to determine the behaviors and similarities of metals in each fraction. While Mn, Pb, and Zn exhibited subjective behaviors in the acid-soluble fraction, Cd, Co, Cu, Cr, and Ni exhibited similar behaviors with each other.

Electrochemical Behavior of Formoterol Fumarate and Its Determination in Capsules for Inhalation and Human Serum using Differential-Pulse and Square-Wave Voltammetry

The electrochemical oxidation of formoterol fumarate (formoterol) has been carried out in aqueous solution in the pH range of 1.5–10.0 by cyclic, linear sweep, differential-pulse and square-wave voltammetry. The diffusion controlled nature of the waves was established. The mechanism of oxidation was discussed. Two voltammetric techniques for the determination of formoterol in 0.5 M sulfuric acid which allow quantitation over the 8×10−6–6×10−5 M range for both methods were proposed. Based on this study simple, rapid and selective two voltammetric methods were developed for the determination of formoterol in capsule dosage form and human serum.

Determination of heavy metals in sediments of the Ergene River by BCR sequential extraction method

Utilizing the sequential extraction procedure (acid soluble, reducible, oxidizable, and residual) proposed by The European Community Bureau of Reference (BCR), the trace metals present in the sediments of the Ergene River, Turkey, were determined. The sediment samples were collected from 10 sampling sites and analyzed to identify the concentrations of cadmium, cobalt, chromium, copper, manganese, nickel, lead and zinc. The flame atomic absorption spectrometer was used for metal determination. The validation of the results was checked by the analysis of the BCR-701 standard reference material. The relationship existing between the sediment characteristics and metal fractions was identified using the correlation analysis. Hierarchical cluster analysis was performed to find out the grouping of the sampling sites based on the similarities of the heavy metals in the bioavailable fraction. When the extractable amounts of heavy metals are considered, the quantity of the mobile fractions (viz., acid soluble, reducible, and oxidizable) of the heavy metals is observed to be higher when compared with that of the immobile fraction (residual). This might be caused by the anthropogenic sources. Besides, it was statistically discovered that the organic matter, pH and clay contents could influence the bonding of the analyte metals in various forms. The cluster analysis revealed three clusters of the sampling stations, with group I (S5-8) and group II (S3, S4 and S9) showing higher environmental risks. The risk assessment code indicated that the highly mobile soluble fractions of Mn, Zn, Cd and Co created a high environmental risk which could result in negative impacts on the aquatic biota.

Seasonal concentrations of some heavy metals (Cd, Pb, Zn, and Cu) in Ulva rigida J. Agardh (Chlorophyta) from Dardanelles (Canakkale, Turkey)

In this study, changes in heavy metal accumulation in U. rigida J. Agardh taxon and seawater have been investigated with respect to different stations and seasons. For this purpose, the severity of heavy metal pollution in the Dardanelles has been presented through the determination of Cu, Pb, Zn, and Cd concentrations in U. rigida macroalgae and seawater taken seasonally from the stations located on six different regions on the strait. While the metal concentrations in alga specimens were found to be high in spring and winter in all stations; the metal concentrations in the seawater, particularly the Pb concentration, were found to be high in all seasons.

Direct Quantitative Determination of Total Arsenic in Natural Hotwaters by Anodic Stripping Voltammetry at the Rotating Lateral Gold Electrode

A simple, rapid, selective and sensitive differential pulse anodic stripping voltammetric (DPASV) technique for the direct quantitative determination of inorganic total arsenic in natural hotwater was developed. The electrochemical de- termination of total arsenic has been carried out at the novel rotating lateral gold electrode in hydrochloric acid solution (37 % w/w). The analysis was performed with a special gold electrode whose active surface was located on the side. Re- productivity of measurement was achieved by the conditioning of the gold electrode. This was done every day before the measurements as well as when the background current varied strongly from measurement to measurement. The determina- tion limit of 0.5 � g L -1 was achieved with 10 mL sample solution. The total arsenic concentration was made by appropri- ate selection of the deposition potential. During the deposition step, the total arsenic content was reduced at -1200 mV by nascent hydogen to As o . During the subsequent voltammetric determination, the preconcentration As o was again oxidized to determine the level. The method was applied successfully to the direct quantitative determination of total inorganic ar- senic in hotwater. In order to show the accuracy of the results developed from voltammetric technique, the values obtained were compared with those obtained from inductively coupled plasma mass spectrometry (ICP-MS).

Electrocatalytic oxidation of hydrazine on poly(4-aminobenzene sulfonic acid)-modified glassy carbon electrode

Electrocatalytic oxidation of hydrazine (HZ) was studied on an stable modified glassy carbon electrode (GCE) based on poly (4-aminobenzene sulfonic acid) (4-ABSA) film. The 4-ABSA-modified glassy carbon electrode was prepared by electrochemical polymerization technique in phosphate buffer solution (PBS) (pH 7.0) and its electrochemical behavior were studied by cyclic voltammetry (CV). The polymer filmmodified electrode has very high catalytic ability for electrooxidation of HZ, which appeared as a reduced overpotential in a wide operational pH range of 5–10. Limit of detection (LOD) and limit of quantification (LOQ) were obtained as 1.31 × 10–7 and 4.35 × 10–7 M for CV; 7.89 × 10–8 and 2.63 × 10–7 M for CA, respectively. The results of experiments showed that prepared modified electrode have good stability, sensitivity and reproducibility for at least one month if stored dry in air.

Results of heavy metals and other water quality levels in tap water from Çan sourced from Ağı Dağı (Mt. Ağı) (Çanakkale, Turkey)

In this study, the concentrations of heavy metals Pb, Cu, Zn, Cd, Ni, Fe, Mn and Cr were determined using an inductively coupled plasma and optical emission spectrophotometer (ICP-OES), and water quality parameters pH, temperature, and conductivity were measured using the YSI 556 MPS water probe. The water samples were collected monthly from five different street tap water points sourced from Mt. Agi (Ağı Dağı in Turkish) spring waters between May 2012 and February 2013 in Çan (Canakkale, Turkey). All results were compared with the drinking water standards of the Turkish Standards Institute (TSE 266), World Health Organization, European Union and US Environmental Protection Agency. While concentrations of Cu, Zn, Fe, and Mn were within limit values, Pb, Cd, Ni, and Cr were at undetectable limits. The highest concentrations of Cu, Zn, Fe, and Mn were 0.010 ppm, 0.018 ppm, 0.058 ppm, and 0.014 ppm, respectively. The findings revealed that although there was no public health risk in view of heavy metal concentrations, there was an acidity problem due to lower pH levels correlated with some heavy metals such as Cu (R = 0.419), Fe (R = -0.421) and Mn (R = -0.687).

Chemical composition, antimicrobial, antioxidant and anthocyanin activities of mosses (Cinclidotus fontinaloides (Hedw.) P.Beauv. and Palustriella commutata (Hedw.) Ochyra) gathered from Turkey

Abstract Cinclidotus fontinaloides (Hedw.) P. Beauv. and Palustriella commutata (Hedw.) Ochyra were used in this study. The chemical composition of mosses in the ethanol and water extract was determined using GC-MS and FT-IR. Antioxidant activities of moss extracts were tested by total phenol and ABTS methods. Trolox equivalent value (TEAC) of mosses was calculated as 26 ± 0.32 and 10 ± 0.22 mg/g. The amounts of the flavonoid compounds were calculated as mg gallic acid. Gallic acid equivalent value of mosses was calculated as 587 ± 0.55 and 496 ± 0.22 mg/g. The extracts antimicrobial activity was tested against Escherichia coli (ATCC 8739), Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 10145) and Candida albicans (ATCC 10231). Significant antibacterial effect was observed for C. fontinaloides and P. commutata in ethanol extract. Total anthocyanin activities of C. fontinaloides and P. commutata were determined as 50 ± 0.17 and 144 ± 0.33 mg/L.

Variations in Nitrogen (NH4+, NO2-, NO3-) and Heavy Metal (Al and Cu)Levels of Water from Swimming Pools in the City Center and Districts ofCanakkale, Turkey

In this study, some nitrogen (NO2-, NO3-, NH4+) and metal (Al and Cu) concentrations were analyzed during the summer period by using an ultraviolet-visible (UV-VIS) spectroscopy method in a total of 44 swimming pools located in the province and districts of Canakkale (Turkey). Merck Kits equivalent to EPA, APHA, ISO and DIN standards were used for spectrometric analyses. The monthly quality parameter results in this study were evaluated according to various limit standard values for different countries. As a result, NH4+, NO2-, NO3-, Al and Cu concentrations varied between 0.003 and 0.999 mg L-1 (0.073 ± 0.139 mg L-1), 0.042 and 0.277 mg L-1 (0.086 ± 0.039 mg L-1), 0.054 and 76.844 mg L-1 (12.111 ± 10.487), 0 and 0.652 mg L-1 (0.141 ± 0.068 mg L-1) and 0 and 2.216 mg L-1 (0.139 ± 0.163 mg L-1), respectively. Although all the maximum values, except for NO2-, exceeded the limit values of the Turkish Health Ministry (THM), all the average values were under the limit values of THM.

Quantitative Clinical Diagnostic Analysis of Acetone in Human Blood by HPLC: A Metabolomic Search for Acetone as Indicator

Using high-performance liquid chromatography (HPLC) and 2,4-dinitrophenylhydrazine (2,4-DNPH) as a derivatizing reagent, an analytical method was developed for the quantitative determination of acetone in human blood. The determination was carried out at 365 nm using an ultraviolet-visible (UV-Vis) diode array detector (DAD). For acetone as its 2,4-dinitrophenylhydrazone derivative, a good separation was achieved with a ThermoAcclaim C18 column (15 cm × 4.6 mm × 3 μm) at retention time (t R) 12.10 min and flowrate of 1 mL min−1 using a (methanol/acetonitrile) water elution gradient. The methodology is simple, rapid, sensitive, and of low cost, exhibits good reproducibility, and allows the analysis of acetone in biological fluids. A calibration curve was obtained for acetone using its standard solutions in acetonitrile. Quantitative analysis of acetone in human blood was successfully carried out using this calibration graph. The applied method was validated in parameters of linearity, limit of detection and quantification, accuracy, and precision. We also present acetone as a useful tool for the HPLC-based metabolomic investigation of endogenous metabolism and quantitative clinical diagnostic analysis.