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    ANTIMICROBIAL ACTIVITY OF TURKISH CITRUS PEEL OILS
    (Pakistan Botanical Soc, 2009) Kirbaslar, F. Guelay; Tavman, Aydin; Duelger, Basaran; Tuerker, Guelen
    The samples of the Citrus fruits viz., lemon (Citrus limon (L.) Burm. f.), grapefruit (Citrus paradisi Macfayden), bergamot (Citrus bergamia Risso et Poit.), bitter orange (Citrus aurantium L.), sweet orange (Citrus sinensis (L.) Osbeck), mandarin (Citrus reticulata Blanco) were collected from southern Turkey (Antalya) in November 2006 and their peel oils were obtained by cold-pressing process. The antimicrobial activities of Turkish Citrus peel oils were evaluated using the disk diffusion method toward 9 bacteria and the results compared with those for penicillin-g, ampicillin, cefotaxime, vancomycine, oflaxacin and tetracycline. Antifungal activities were reported for Kluyveromyces fragilis, Rhodotorula rubra, Candida albicans, Hanseniaspora guilliermondii and Debaryomyces hansenii yeasts, and the results were referenced against nystatin, ketaconazole and clotrimazole antifungal agents. The Citrus peel oils showed strong antimicrobial activity against the test organisms. Lemon and bergamot peel oils have a little higher activity than the other Citrus peel oils.
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    Öğe
    Osteryoung square wave voltammetric determination of phenazopyridine hydrochloride in human urine and tablet dosage forms based on electrochemical reduction at carbon paste electrode
    (Bentham Science Publ Ltd, 2007) Citak, Meryem; Yilmaz, Selahattin; Dilgin, Yusuf; Tuerker, Guelen; Yagmur, Sultan; Erdugan, Hueseyin; Erdugan, Necla
    An electroanalytical method was developed for the direct quantitative determination of phenazopyridine hydrochloride (PAP) or in other words, pyridium, in spiked human urine and tablet dosage forms. The electrochemical reduction and determination of PAP were carried out at carbon paste electrode (CPE) in various aquaeous Solution in the pH range of 0.5-12.30 by (CV) and osteryoung square wave voltammetry (OSWV). The best results were obtained for the quantitative determination of PAP by OSWV method in 0.5 mol L-1 Sulfuric acid at about pH 0.51. The peak current and peak potential depend on pH and scan rate were studied. The diffusion controlled nature of the peak was established. This electroanalytical procedure made it possible to determine PAP in the concentration range 2.5x10(-8)-2.5x10(-6) mol L-1. Limit of detection (LOD) and limit of quantification (LOQ) were obtained as 7.5x10(-9) and 2.5x10(-8) mol L-1 respectively. Precision and accuracy of the developed method were checked by recovery studies in spiked urine and tablet dosage forms.
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    Öğe
    Speciative determination of Cr(III) and Cr(VI) in dyeing waste water of Dil Creek discharge to Izmit Gulf (Izmit-Kocaeli, Turkey) by ICP-AES
    (Springer, 2008) Oktor, Kadriye; Yilmaz, Selehattin; Tuerker, Guelen; Erkus, Esra
    Wastewater pollution in industrial areas is one of the most important environmental problems. Heavy metal pollution, especially chromium pollution in wastewater sources from dyeing and tannery has affected the life on earth. This pollution can affect all ecosystems and human health directly or by food chain. Therefore, the determination of chromium in this study is of great importance. Dil Creek is located in the eastern Marmara region and discharges into the Izmit Gulf. This water source is used for irrigation in agriculture and as drinking water for animals. In this study, a rapid, sensitive and selective method for the speciative direct determination of Cr (III) and Cr (VI) in dyeing waste water samples collected from the nearest station to Izmit Gulf of Dil Creek in May 2006 by inductively coupled plasma-atomic emission spectrometry (ICP-AES) has been developed. An analysis of a given sample is completed in about 15 min for ICP-AES the method. As the result of the chromium analysis, the limit of quantification (LOQ) for the Cr (III), Cr (VI) and total Cr were founded as 0.0111 +/- 0.0002 mg/l (RSD, 1.80%), 0.0592 +/- 0.0010 mg/l (RSD, 1.70%) and 0.0703 +/- 0.0020 mg/l (RSD, 2.84%) respectively. In addition, the general mathematical formula has been developed to calculate the concentration of Cr(III), which can be applied to any other metal species. The result of Cr (VI) analysis indicated that water quality of Creek was IV. class quality according to the inland water classification. In order to validate the applied method, recovery studies were performed.