Ümit Ay

Chemometric evaluation of the heavy metals distribution in waters from the Dilovası region in Kocaeli, Turkey

The main objective of this study was to test water samples collected from 10 locations in the Dilovası area (a town in the Kocaeli region of Turkey) for heavy metal contamination and to classify the heavy metal (Cr, Mn, Co, Ni, Cu, Zn, As, Cd, Pb and Hg) contents in water samples using chemometric methods. The heavy metals in the water samples were identified using inductively coupled plasma-mass spectrometry (ICP-MS). To ascertain the relationship among the water samples and their possible sources, the correlation analysis, principal component analysis (PCA), and cluster analysis (CA) were used as classification techniques. About 10 water samples were classified into five groups using PCA. A very similar grouping was obtained using CA.

Interferences in the quartz tube atomizer during arsenic and antimony determination by hydride generation atomic absorption spectrometry

Abstract Interferences of some metals in the determination of arsenic by hydride generation atomic absorption spectrometry utilizing a quartz tube atomizer were studied. The atomizers were coated under vacuum with Ni, Au, Pd and Cr. The arsenic signal was almost totally suppressed by all the metal coatings and thus the interferences from metal ions in the determination of arsenic were attributed both to the carry over of the reaction mixture, as well as interferences in the hydride formation step. Inter-element interferences by arsenic and antimony on each other in the atomizer of the same system were also studied. When arsine and stibine reach the atomizer at the same time they suppress each other’s signals. The interference of arsenic on antimony was eliminated by simply separating arsine, which elutes first, from stibine using a simple gas chromatographic column (GC column). However, even when arsine and stibine are separated using the GC column, antimony is deposited in the quartz tube atomizer at the temperatures the quartz tube attains when heated in the air–acetylene flame, suppressing the arsenic signal in subsequent experiments. Therefore, directing of stibine outside of the atomizer, after elution of arsine from the GC column, was suggested for arsenic determination.

Novel inorganic–organic hybrid polymers to remove heavy metals from aqueous solution

AbstractPoly-GPTS was prepared by polymerization of 3-glycidyloxypropyltrimethoxysilane (GPTS) with potassium tert-butoxide (KOtBu) at 50°C. After this stage, adsorbents poly-GPTS and poly-GPTS/Ti(O)/OH were prepared from hydrolysis of poly-GPTS and mixtures between poly-GPTS and titanium isopropoxide in 1:1 mol ratio. The hydrolysis was carried out in 50 ml of isopropanol with 0.1 M HCl. The characterizations of the adsorbents were performed by elemental analysis, thermogravimetric, and spectroscopic methods. After hydrolysis, it was seen that isopropoxide and methoxide groups were removed from the adsorbents under the studied conditions because of the condensation reactions. Pb2+, Cu2+, and Cd2+ ions were removed from the aqueous solution using these hybrid polymers as adsorbents. Influence factors such as the initial pH, adsorption time, the amounts of adsorbent, and solution concentrations on Pb2+, Cu2+, and Cd2+ adsorptions were investigated. The study showed that they were very good adsorbents for r...

Atomic Absorption Spectrometry Determination of Cd, Cu, Fe, Ni, Pb, Zn, and Tl Traces in Seawater Following Flotation Separation

ABSTRACT A fast method for separation of Cd, Cu, Fe, Ni, Pb, Zn, and T1 from seawater before their determination by atomic absorption spectrometry (AAS) is described. The ability of Co(III) hexamethylenedithiocarba-mate, Co(HMDTC)3, as a flotation collector for metals from seawater was investigated. The influence of pH of the media, as one of the crucial parameters for effective flotation, as well as mass of cobalt as one of the constituents of a chelatometric collector was optimized. The used mode of atomization flame (FAAS) or electrothermal (ETAAS) depends on the concentration level of analyte present in the seawater sample investigated. The AAS method following flotation was compared with the method of inductively coupled plasma-atomic emission spectrometry (ICP-AES). The limit of detection (LOD) of each analyte obtained by FAAS or ETAAS is determined: flotation/ETAAS for Cd is 0.010 µg/L, for Cu 0.034 μg/L, for Ni 0.305 µg/L, for Pb 0.290 µg/L, and for Tl 0.032 µg/L, whereas flotation/FAAS for Fe is 0.890 µg/L and for Zn 0.994 mg/L.

Separation of Tl(I) and Tl(III) from environmental water samples by flotation method coupled with Zeeman ETAAS determination.

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 cobalt(III) hexamethylenedithiocarbamate as a colloidal precipitate collector for simultaneous flotation separation of Tl(I) and Tl(III) from water matrices was studied. All experimental parameters influencing a proper flotation of both thallium ions were ascertained. The developed procedure with Co(HMDTC)3 is applied for preconcentration and separation of total thallium in water matrix before ZETAAS. The results of ZETAAS analysis are compared with those obtained by inductively coupled plasma-atomic emission spectrometry. The ZETAAS limit of detection of thallium preconcentrated by Co(HMDTC)3 is 0.031 μ g/L.

Cobalt(III) Hexamethylenedithiocarbamate as a New Collector for Flotation Preconcentration of Iron, Nickel, Lead, and Zinc Prior to ETAAS

Abstract A fast method for separation of iron, nickel, lead, and zinc from water matrices prior to their atomic absorption spectrometry (AAS) is described. The separation and preconcentration of metals was performed by precipitate colloid flotation with cobalt(III) hexamethylenedithiocarbamate, Co(HMDTC)3, as a new collector. The optimal conditions for flotation of each analyte by Co(HMDTC)3 were determined. After flotation separation analytes were analyzed by flame atomic absorption spectrometry (FAAS) or electrothermal atomic absorption spectrometry (ETAAS) depending of their concentrations in the water sample. The results of AAS analyses are compared with those obtained by inductively coupled plasma‐atomic emission spectrometry. The limit of detection of analytes was determined 0.838 µg/L for iron and 1.105 µg/L for zinc using FAAS and 0.129 µg/L for lead and 0.113 µg/L for nickel by ETAAS.

The effect of heavy metals on the anthracene–Me-β-cyclodextrin host–guest inclusion complexes

Anthracene was used to form an inclusion complex with methylated-β-cyclodextrin (Me-β-CD) in water. In aqueous Me-β-CD solution, typical fluorescence emission of anthracene was observed. Benesi–Hildebrands method was used to obtain the stoichiometry of the anthracene–Me-β-CD complex. The Stern–Volmer quenching constants, Ksv, and fluorescence quantum yields were calculated according to changes in the fluorescence emission intensity of anthracene–Me-β-CD inclusion complexes by adding various amounts of Pb2+ and Cd2+ salts in water. The Ksv values and fluorescence quantum yields indicate that Pb2+ salts quench the anthracene–Me-β-CD inclusion complexes more efficiently than Cd2+ salts.

Spectrophotometric determination of total inorganic arsenic with hexamethylene ammonium-hexamethylenedithiocarbamate in nonionic triton X-100 micellar media

We have developed a cost-effective and sensitive spectrophotometric method for the determination of arsenic at trace level using a new reagent, hexamethylene ammonium-hexamethylenedithiocarbamate (HMA-HMDTC). Here we show that arsenic reacts with HMA-HMDTC in acidic conditions to yield the As(HMDTC)3 complex. We studied the Beer’s law at 256 nm, which showed linearity over the concentration range 0.2–1.0 µg/mL of arsenic. We have shown that molar absorptivity, Sandell’s sensitivity and the detection limit of the method are 6.06 × 104 L/mol cm, 0.0012 μg/cm2 and 0.060 μg/mL, respectively. We have applied this new method to the determination of arsenic in drinking water.

Investigation of heavy metal pollutants at various depths in the Gulf of Izmit

In this study, we report results concerning the accumulation of heavy metals in seawater from Izmit Bay. The bay was divided into the three parts: the eastern, the central and the western basins. The goal of this study was to determine levels of heavy metals at various depths in the bay between April 2008 and May 2010. Liquid-liquid extractions were performed on seawater samples. An atomic absorption spectrophotometer was used to measure levels of six metals: lead, cadmium, chromium, iron, manganese and zinc. We applied our results to evaluate the status of pollution in the Gulf of Izmit. Significant seasonal differences in metal concentrations and higher concentrations of many metals in water near the shore are evidence for uncontrolled release of pollutants in the water.