Browsing by Author "Vural, Nilufer"

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Application of Solid-Phase Micro-Extraction (Spme) for Determining Residues of Chlorpyrifos and Chlorpyrifos-Methyl in Wine With Gas Chromatography (Gc)
(inst Brewing, 2007) Anli, Ertan; Vural, Nilufer; Vural, Halil; Gucer, Yalcin
The incorrect use of insecticides in many countries' vineyards may result in some toxicological risks for the consumers by their presence on the grapes. In this research, a rapid gas chromatographic method was used for the determination of the residue levels of two organophosphorus pesticides (chlorpyrifos and chlorpyrifos-methyl) in wine. Pesticides are described and compared with each other. Ten red wines from two different regions of Turkey were analyzed for their chlorpyrifos and chlorpyrifos-methyl content. The samples were diluted with water and extracted by solid-phase micro extraction. Nitrogen-Phosphorus Detection (NDP) and Electron-Capture Detection (ECD) were used to identify and quantify the pesticides, the findings being confirmed using Mass Spectrometric Detection. Individual detection limits were in the range of (chlorpyrifos) 0.02-(chlorpyrifos-methyl) 0.1 ng. Limits of quantification varied from (chlorpyrifos) 0.01-(chlorpyrifos-methyl) 0.05 mg kg(-1). The maximum residues limits of the two pesticides in the Turkish wines examined were much lower than the Turkish and European Union limits.
Determination of the Principal Volatile Compounds of Turkish Raki
(inst Brewing, 2007) Anli, R. Ertan; Vural, Nilufer; Gucer, Yalcin
Turkish Raki is a type of traditional aniseed spirit produced in different areas of Turkey. The amounts and the repartition of the alcoholic fermentation products (fusel alcohols, esters, and aldehydes) are mainly responsible for the flavours and quality of the spirit. Previous studies have been carried out on the quantification of the volatiles of the different aniseed spirits using GC and GC-MS. In this study of 20 different commercial brands of bottled Raki and 5 homemade Turkish Raki products, the major volatiles and methanol were determined using direct injection with GC-MS. SPME extraction was also used as a confirmation method for the separation of Raki volatiles. Eight different substances were successfully identified using SPME extraction. The results indicated that some homemade Turkish Raki products from the different regions contained slightly higher concentrations of the most studied compounds. The toxic compound methanol was detected only at a level far below the acceptable legal limit.