Seref Gucer

Fractionation and speciation of Cu, Zn and Fe in wine samples by atomic absorption spectrometry

Abstract A scheme is presented for fractionation of wine components and Fe, Cu and Zn determination in different fractions. The charge of the metal species was established using cation and anion exchange separation based on solid phase extraction. The resin XAD-8 was used for the separation of wine polyphenols in complexes with wine proteins and polysaccharides. Dowex ion exchange resins were used for the separation of cationic and anionic species of Fe, Cu and Zn. Flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry were used off-line for the quantitative determination of metals in the different fractions obtained.

Flow-injection speciation of aluminium

Abstract This review discusses recent trends in chemical speciation of aluminium in natural waters. Several difficulties which arise from the complexity of aluminium species present in natural samples as well as its participation in dynamic equilibrium are highlights. Taking this into account various approaches for speciation of Al described in the literature are critically evaluated. The strategy of fractionation procedures based on the rate of reaction, sorption efficiency, chromatographic behaviour of the aluminium compounds or size of the molecules are described in the paper. Besides conventional procedures involving various measuring and separation techniques, a special emphasis is focused on mechanised flow injection methodologies. This was found to be very important in order to ensure precise control of the reaction time, which is essential in aluminium species equilibrium system. The analytical performance of several separation procedures based on flow injection approaches as well as the detection methods are discussed and compared.

Speciation of lead in soils and relation with its concentration in fruits

Abstract The lead concentrations of the fruit samples were determined by using slotted tube atom trap (STAT)-enrichment-flame and graphite furnace atomic absorption spectrometry (FAAS and GF-AAS). The soil samples related to these fruits were also analysed for Pb after extraction with various chemical reagents. The relation between the fruit-lead and soil-extractable lead concentrations was examined in order to explain the bioavailability of lead. A linear relation was observed between the hot Na2EDTA extraction-soluble Pb contents in the soil and the Pb concentrations in the mulberry (R2=0.95), strawberry and apple grown on these soils. Probable chemical forms of lead in soil were evaluated. Acceptable agreement (at least 91%) was achieved between the results of STAT-enrichment-FAAS and GF-AAS.

Determination of vanadium in vegetable matter by flame atomic absorption spectrometry

A method is described for the preconcentration of trace amounts of vanadium(V) from biological samples and its determination by flame atomic absorption spectrometry. It was found that the optimum acidity is in the pH range 2.9–4.9. An increase in the interferences from Al, Mg and Ca is observed. Elimination of these problems was achieved by adding an enrichment step to the analytical scheme. Linear calibration was obtained over the concentration range 10–120 ppb. The relative standard deviation was found to be 3% for a vanadium concentration of 100 ppb. The proposed enrichment method was applied to the determination of vanadium in foods and plants. The preconcentration system enables a 300-fold enrichment of vanadium(V) to be achieved, and therefore its determination at ppb levels. The proposed method tolerates the presence of a large number of cations that are usually found with vanadium in plant and animal tissues.

Element Content (Cu, Fe, Mn, Ni, Pb, and Zn) of the Ruderal Plant Verbascum olympicum Boiss. from East Mediterranean

In this study, heavy metal content (Cu, Fe, Mn, Ni, Pb, Zn) was determined in soils and different organs of Verbascum olympicum Boiss. This species is endemic to Uludağ and spreads on destroyed areas such as: roadsides, developed building areas, ski lift stations and sheep folds. Soils and different organs (roots, stems, leaves and flowers) of plant samples were analyzed using an atomic absorption spectrophotometer for determining the element content. Heavy metal contents in soils and different organs in this species were highly correlated (P < 0.05). However, the contribution of plant organs to the accumulation capacity varied according to the metal. These results suggest that this species may be useful as a bioindicator for heavy metals.

Common Vetch ( Vicia sativa L.) Germplasm: Correlations of Crude Protein and Mineral Content to Seed Traits

In order to increase knowledge of seed nutritive value and to demonstrate its relationship in common vetch (Vicia sativa L.) germplasm, 388 common vetch accessions were grown under field conditions in 2008–2009 growing season in Bursa province of Turkey. Seeds were analyzed for seed minerals (Ca, Cu, Mg, Mn, P, S, Zn and K) and crude protein (CP) content. The accessions were grouped according to testa and cotyledon color and seed size, and the results were evaluated by analysis of variance to determine relationships between minerals and CP content, testa and cotyledon colors, and seed weight. In general, there was no significant difference between testa colors or cotyledon colors in minerals and CP content. However, seed weight was closely associated with minerals and CP contents in this study. Analysis of variance and correlation analysis showed that seed weight was closely associated with some minerals and CP content. The small seeds had significantly higher Ca, Cu, Mg, Mn, S, Zn and CP contents than medium and large seeds.

Fractionation analysis of manganese in Turkish hazelnuts (Corylus avellana L.) by inductively coupled plasma-mass spectrometry.

In this study, an analytical fractionation scheme based on water, diethyl ether, n-hexane, and methanol extractions has been developed to identify manganese-bound fractions. Additionally, in vitro simulated gastric and intestinal digestion, n-octanol extraction, and activated carbon adsorption were used to interpret the manganese-bound structures in hazelnuts in terms of bioaccessibility. The total content of manganese in the samples was determined by inductively coupled plasma-mass spectrometry after microwave-assisted digestion, and additional validation was performed using atomic absorption spectroscopy. Water fractions were further evaluated by high-performance liquid chromatography hyphenated to inductively coupled plasma-mass spectrometry for the identification of water-soluble manganese fractions in hazelnut samples. The limits of detection and quantification were 3.6 and 12.0 μg L(-1), respectively, based on peak height.

Fractionation analysis and bioavailability of manganese in spinach (Spinacia oleracea L.) leaves

Abstract This paper introduces a fractionation scheme using water, acetone, chloroform, diethyl ether, ethanol, n-hexane, and methanol as extractants for the determination of manganese in spinach samples by inductively coupled plasma-mass spectrometry (ICP-MS). Simulated gastric and intestinal digestions as well as n-octanol extraction and activated carbon adsorption were performed for the bioavailability assessments. Comparative studies of the various extraction treatments were evaluated for confirmation analysis. The total elemental concentrations were determined after digesting the samples in a microwave digestion system. The method validation parameters were defined in terms of the detection limits, accuracy, and precision. Additional validation was performed by comparing the ICP-MS method with atomic absorption spectrometry. The limits of detection and quantification were 0.046 and 0.154 mg kg-1, respectively. Additionally, the repeatability and reproducibility, calculated from the relative standard deviation (%RSD), were 2.4% and 3.7%, respectively.

Characterization of Copper Bioavailability in Wheat Flour by Chemical Fractionation and Inductively Coupled Plasma–Mass Spectrometry

ABSTRACT The bioavailability of copper in wheat flour is reported based on chemical fractionation using water, diethyl ether, n-hexane, methanol, acetone, and chloroform/methanol to identify copper-bound matrix sites. The total copper concentrations in the fractions were determined by inductively coupled plasma-mass spectrometry. In vitro gastrointestinal digestion was performed using pepsin and pancreatin enzyme solutions at defined pH values for bioavailability studies. The bioavailable forms of copper in the samples were 61–80% of the total concentration. Extraction with n-octanol and activated carbon adsorption studies were evaluated to compare their efficiencies to the enzymatic approach.

An alternative method for screening of Sudan dyes in red paprika paste by gas chromatography-mass spectrometry

An indirect analytical screening method for Sudan dyes by gas chromatography mass spectrometry was developed as an alternative method to novel liquid chromatography mass spectrometry. Red paprika paste samples were extracted with acetone and centrifuged at room temperature. The supernatant was removed from the solution and buffered. The reduction step is performed chemically with sodium dithionite and corresponding dyes as amine products were identified by GC-MS. The method was validated for analytical properties using spiked paste samples. Several parameters which may influence the reduction procedure, such as temperature and the amount of reducing agent, were optimized using central composite design methodologies for Sudan III in order to increase its lower apparent recovery as compared with the others. Optimum conditions for Sudan III were found to be 45 °C and 1.3 M by using a central composite design. The apparent recovery values were 77.6%, 69.4%, 51.3%, 42.5% with relative standard deviations of 31.8%, 20.4%, 20.3%, 31.2% for Sudan I, II, III, IV dyes respectively. This method was used successfully for screening of Sudan dyes in paprika paste products by GC-MS.