Yazar "Oflu, Sude" seçeneğine göre listele

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  • Küçük Resim
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    Development of analytical strategy for the determination of cadmium by flame atomic absorption spectrometry after dithizone/deep eutectic solvent probe based liquid phase microextraction
    (Taylor & Francis, 2024) Akbıyık, Hilal; Serbest, Hakan; Kılınç, Yağmur; Oflu, Sude; Gürsoy, Selim; Özdoğan, Nizamettin; Çetin, Gülten; Bakırdere, Sezgin
    Liquid phase microextraction (LPME) with a dithizone/deep eutecticsolvent (DTZ-DES)-based probe was employed for the determinationof trace cadmium by flame atomic absorption spectrometry (FAAS).All extraction parameters were univariately optimized to achieve thehighest efficiency and the limits of detection and quantification were3.5 and 11.8 ng mL−1. Good linearity was obtained from 10 to200 ng mL−1 with a regression coefficient (R2) of 0.9979. The sensitiv-ity of FAAS system was improved 26.9-fold by the microextractionprocedure. The accuracy and applicability of the method were inves-tigated with recovery experiments carried out using corn silk teaextracts. The recovery values with matrix matching calibration werefrom 81.3 to 114.3%, demonstrating that this environmentallyfriendly method is applicable for determination of cadmium in teasamples with good accuracy.
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    Efficient removal of estrone and 17β‑estradiol from aqueous medium using UV irradiation‑assisted fenton process
    (Springer Link, 2024) Dikmen, Yaren; Şaylan, Meltem; Oflu, Sude; Fırat Ayyıldız, Merve; Serbest, Hakan; Dalgıç Bozyiğit, Gamze; Bakırdere, Sezgin
    The endocrine-disrupting compounds (EDCs) have high-risk implications for public health and the environment due to their potential to interfere with endocrine system functions. This study is based on an evaluation of the applying the UV-assisted Fenton process for the removal and degradation of 17β-estradiol and estrone in aqueous medium. The simple and affordable UV irradiation system was developed and applied to accelerate the Fenton reaction. High performance liquid chromatography (HPLC) was employed for the quantitative measurements of estrogenic hormones at 230 nm, which is highly sensitive and capable of accurately measuring hormones within 15 min. The LOD/LOQ values of HPLC system were recorded to be 0.03/0.11 mg/kg and 0.05 /0.15 mg/kg for estrone and 17β-estradiol, respectively. Fe3O4 magnetic nanoparticles and iron (II) sulfate solution were evaluated as appropriate iron sources under fixed UV irradiation to assess the Fenton process. The main parameters, namely hydrogen peroxide (H2O2) amount, iron (II) sulfate amount, pH, and UV irradiation period, were optimized univariately for determining the optimum conditions. The optimum conditions were recorded to be: 0.70 mL of pH 3.0 buffer solution, 1.25 mL of H2O2, 0.80 mL of 100 mg/L Fe2+ solution, and an irradiation time of 60 min. The removal experiments were also carried out on domestic wastewater to validate the system’s applicability. The percent removal efficiencies of both estrogenic hormones were calculated at higher than 99%. These results showed that high efficiency was achieved within the detection limits of the HPLC system. This proves the possibility of complete degradation of the analytes and their efficiency and practicality for pollution control and water quality improvement in future studies.
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    Implementation of simple and effective fine droplet formation-based spray-assisted liquid phase microextraction for the simultaneous determination of twenty-nine endocrine disruptor compounds and pesticides in rock, soil, water, moss, and feces samples from antarctica using gas chromatography-mass spectrometry
    (Springer, 2024) Zaman, Buse Tuğba; Dalgıç Bozyiğit, Gamze; Şaylan, Meltem; Koçoğlu, Elif Seda; Kartoğlu, Bedrihan; Aydın, Efe Sinan; Girgin, Ayça; Borahan, Tülay; Oflu, Sude; Kılınç, Yağmur; Bakırdere, Emine Gülhan; Bakırdere, Sezgin
    This study established the simultaneous determination of the selected endocrine-disrupting compounds (EDCs) and pesticides in rock, soil, water, moss, and feces samples collected from the Antarctic region. The spray-assisted droplet formation-based liquid phase microextraction (SADF-LPME) coupled to GC–MS system was developed and validated for the screening and monitoring of 29 selected EDCs and pesticides. Binary solvent system, 1:1 (v/v) dichlormethane: 1,2-dichloroethane mixture was employed as an extraction solvent and sprayed onto sample or standard solutions using a straightforward and practical spray apparatus. The factors afecting the extraction process such as extraction solvent type and ratio, extraction solvent volume (spray repetition), vortexing period, and sample pH were properly optimized. Analytical fgures of the merit of the method were recorded under the optimal extraction/chromatographic conditions. The LOD, LOQ, and enhancement factor were in the range of 1.0 to 6.6 ng/g, 3.2 to 22.1 ng/g, and 3.7 to 158.9, respectively. The method demonstrated a good linear working range for all the selected analytes with proper coefcients of determination. The usability and reliability of the microextraction strategy was confrmed using seawater, moss, and soil samples, and the %recoveries were within an acceptable range (>70%) for all examined samples. The environmental samples collected from the Horseshoe and Faure Islands of the Antarctica region were analyzed to assess the potential pollution of EDCs and pesticides. This method has the potential to be employed for the analysis of EDCs in routine analytical laboratories and for controlling and screening the organic pollutant content of diferent environmental samples.