Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
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Article Citation - WoS: 1Citation - Scopus: 2A Molecularly Imprinted Polymer as Solid Phase Extraction Sorbent for Ketoprofen Determination in Water and Artificial Serum Prior To Hplc(TÜBİTAK - Türkiye Bilimsel ve Teknolojik Araştırma Kurumu, 2022) Shahwan, Talal; Gürel Özyurt, Elif; Özyurt, Ömer; Ölçer, Yekta Arya; Eroğlu, Ahmet Emin; Boyacı, EzelKetoprofen (KET) is an active pharmaceutical compound that has pain relieving and antipyretic effects. Its determination in body fluids and environmental waters is important due to widespread use of the compound. In this study, a selective and reliable method has been developed for the determination of ketoprofen in water and artificial serum using molecularly imprinted polymers (MIPs) as a solid phase extraction sorbent prior to HPLC-DAD detection. The MIP was synthesized by copolymerization of methacrylic acid (MAA) and trimethylpropane trimethacrylate (TRIM) in the presence of ketoprofen as the template. For the sake of comparison, nonimprinted polymer (NIP) was also synthesized under the same experimental conditions without the addition of ketoprofen under the same experimental conditions. Critical extraction parameters such as sample pH, shaking time and sorbent amount were optimized and adjusted to 8.0, 24 h, and 10.0 mg, respectively, for a sample volume of 10.0 mL. MIP showed higher selectivity than NIP towards ketoprofen in an artificial matrix containing another pain relieving drug, ibuprofen, and a cardiovascular drug, metoprolol. The proposed method was successfully applied for the detection of ketoprofen in spiked drinking water, tap water, and artificial serum samples, and showed satisfactory results with respective recoveries of 96.8 % (± 0.8), 93.7% (± 0.6), 62.2% (± 0.6), and 69.9% (± 0.6).Article Citation - WoS: 4Citation - Scopus: 5Recent Progress in Wearable Extractive Sampling Technology(Elsevier, 2022) Kahremanoğlu, Kübra; Tosun Kurtalan, Hazal; Eroğlu, Ahmet Emin; Boyacı, EzelThe inevitable incline in the daily exposure to various chemicals has raised a necessity to monitor the body's exposure and biological responses to these stimuli more comprehensively and easily; conceivably, integrating novel designs, extractive phases, and state-of-the-art instrumentation with the primary aim of taking the chemical snapshot of the system. Wearable extractive devices are promising tools that are present in the analytical toolbox and address the abovementioned needs. These devices consist of a particular class of samplers that an individual can wear without limiting her/his daily life activities. In addition to being wearable, these devices show the ability to preconcentrate the analytes in an extractive phase while integrating the sampling and sample preparation. In addition to being imperative for personal exposure investigations, applications in diagnostic and prognostic health monitoring are among their emerging applications. Besides, in vivo soft samplers based on microextraction techniques provide non-invasive to low invasive approaches for non-lethal monitoring of various biosystems. Although in these applications they are not used in an ‘obvious way’ as wearable devices as they are not placed directly on the subject's skin and are instead immersed under the skin, in the scope of this review they will still be considered to provide a picture for future directions of extractive wearable devices. This review aims to cover the wearable extractive devices used in exposure studies (with a special focus on the last two years), in vivo, and in situ applications (with a focus on the last five years) where reliable information about the system is under interest.Article Citation - WoS: 169Citation - Scopus: 177Thin Film Microextraction: Towards Faster and More Sensitive Microextraction(Elsevier Ltd., 2019) Ölçer, Yekta Arya; Tascon, Marcos; Eroğlu, Ahmet Emin; Boyacı, EzelThin film microextraction (TFME) is an analytical tool that has been proven to be suitable for integrated sampling and sample preparation of a wide variety of routine and on-site applications. Compared to the traditional microextraction techniques, the most important advantage of TFME is its enhanced sensitivity due to the relatively larger extractive phase spread over a larger surface area. The technique, in this way, facilitates fast extraction kinetics and high extractive capacity. Moreover, TFME offers high versatility for device development over classical SPME technologies due to the plethora of available extractive phases, coating methods and geometry options. The goal of this review is to provide a comprehensive summary of the contemporary advances in this exciting field covering novel extractive phases, technological and methodological developments, and relevant cutting-edge applications. Finally, a critical discussion of the future trends on TFME is also presented. (C) 2019 Elsevier B.V. All rights reserved.Article Citation - WoS: 8Citation - Scopus: 10Trypsin-Immobilized Silica: a Novel Adsorbent for V(iv) and V(v) Removal From Water(Water Environment Federation, 2018) Erdem Yayayürük, Aslı; Shahwan, Talal; Şanlı Mohamed, Gülşah; Eroğlu, Ahmet EminIn the present study, trypsin-immobilized silica was employed for the removal of V(IV) and V(V) ions from water. The synthesized sorbent was first characterized and then investigated for the removal of V(IV) and V(V) under various experimental conditions. The adsorption performance of the sorbent was tested as a function of pli, sorbent amount, initial vanadium concentration, contact time, and temperature. The sorption process was then investigated, both from a kinetic perspective and also in terms of isotherm models. The Langmuir adsorption isotherm was the best model to describe the sorption process. Sorption thermodynamics were spontaneous and exothermic. The proposed method was successfully applied to real samples for the removal of V(IV)and V(V) with sufficient accuracy and precision.Article Citation - WoS: 45Citation - Scopus: 46Electrospun Polystyrene Fibers Knitted Around Imprinted Acrylate Microspheres as Sorbent for Paraben Derivatives(Elsevier, 2018) Demirkurt, Merve; Ölçer, Yekta Arya; Demir, Mustafa Muammer; Eroğlu, Ahmet EroğluParabens are used as antimicrobial preservatives in food, cosmetic products and pharmaceuticals regardless of their endocrine disrupting effect. In this study, highly selective molecular imprinted polymers (MIPs) were synthesized in submicron-sizes and converted to an SPME fiber coating through electrospinning process in order to determine parabens in water samples. Conversion of MIP to a fiber is achieved via creation of spacial knitting around MIP by polystyrene. The selectivity and extraction ability of the fibers were compared with the commercial fibers and the corresponding non-imprinted polymer (NIP) coated fiber. The coated fiber showed better extraction ability among them. Also, the results revealed that the fiber has better selectivity for benzyl paraben and the other structurally-related compounds, such as methyl and propyl paraben. Extraction efficiency of prepared fibers for three parabens has been tested by spiking bottled, tap and sea water samples. The recoveries changed between 92.2 ± 0.8 and 99.8 ± 0.1 for three different water types. This method could be used for selective and sensitive determination of parabens in aqueous samples.Article Citation - WoS: 1Citation - Scopus: 1Amalgamation Performances of Gold-Coated Quartz Wool, Alumina, Silica, Sand and Carbon Fiber for the Determination of Inorganic Mercury in Waters by Cold Vapor Atomic Absorption Spectrometry(Pleiades Publishing, 2017) Erdem Şimşek, Arzu; Erdem Yayayürük, Aslı; Shahwan, Talal; Eroğlu, Ahmet EminDifferent gold-coated sorbents for amalgamation were applied for the determination of inorganic mercury in waters using a home-made cold vapor generation unit coupled to atomic absorption spectrometry. Among the gold-coated materials investigated (quartz wool, alumina, silica, sand and carbon fiber) quartz wool was found to give the most efficient results in terms of sorption and release. Analytical performance of the system without and with amalgamation was investigated and it was found that when amalgamation was applied, the linearity and slope of the calibration plots were independent on the sample volume for 1.0, 5.0 and 10.0 mL. Method validation was realized through the analysis of a sample of spring water spiked with 1.0 μg/L inorganic mercury and the spike recoveries were found to be 95 ± 1, 91 ± 3, and 99 ± 5% for 1.0, 5.0, and 10.0 mL, respectively. The results demonstrated that the methodology can be applied to these types of samples directly or after amalgamation, depending on the mercury concentration.Article Citation - WoS: 55Citation - Scopus: 60Development of Molecularly Imprinted Polymers (mips) as a Solid Phase Extraction (spe) Sorbent for the Determination of Ibuprofen in Water(Royal Society of Chemistry, 2017) Ölçer, Yekta Arya; Demirkurt, Merve; Demir, Mustafa Muammer; Eroğlu, Ahmet EminIbuprofen is a well-known endocrine disrupter. In this study, highly selective molecularly imprinted polymers (MIPs) with different morphologies were synthesized via precipitation and bulk polymerization of methacrylic acid (MAA) and trimethylolpropane trimethacrylate (TRIM) in the presence of ibuprofen as a template. Non-imprinted polymers (NIPs) were also synthesized via the same procedure in the absence of ibuprofen. Spherical and monolithic MIPs were obtained using different experimental conditions, and the spherical MIP was shown to have better sorption towards ibuprofen. The optimum sample pH, sorbent amount, sample volume, and sorption time were determined to be 8.0, 25.0 mg, 10.0 mL, and 30.0 min, respectively. A methanol water mixture (MeOH:H2O, 80:20, pH 3.0) was employed as an eluent with >97% (±0.8, n = 3) desorption. The MIP demonstrated high selectivity towards ibuprofen in the presence of naproxen and ketoprofen. The validity of the proposed method was checked via spike recovery tests using drinking and tap water samples. The method worked efficiently for both water types, resulting in the recoveries of 97.2% (±0.3, n = 3) and 97.7% (±0.2, n = 3).Article Citation - WoS: 5Citation - Scopus: 5Use of Amberlite Xad-7hp for the Separation of Mn(ii) and Mn(vii) in Waters(Pleiades Publishing, 2017) Erdem Yayayürük, Aslı; Eroğlu, Ahmet EminA simple method is proposed for the determination and speciation of Mn(II) and Mn(VII) in waters utilizing a macroporous resin, Amberlite XAD-7HP. The batch method was employed and flame atomic absorption spectrometry was used in all determinations. Amberlite XAD-7HP resin was shown to retain Mn(VII) between pH 4 and 12. If the solution contains only one of the species, either Mn(II) or Mn(VII), the resin behaves selectively depending on the pH of the solution. The elution from the sorbent was realized using K2C2O4 in HNO3. The efficiency of the method was checked via spike recovery experiments. The proposed method was successfully applied to industrial wastewater samples and quantitative recoveries (≥96.0%) confirmed the accuracy of the method.Article Citation - WoS: 12Citation - Scopus: 16Carotenoid Profile in Prochlorococcus Sp. and Enrichment of Lutein Using Different Nitrogen Sources(Springer Verlag, 2016) Erdoğan, Ayşegül; Demirel, Zeliha; Eroğlu, Ahmet Emin; Conk Dalay, MeltemVarious carotenoids of the cyanobacterium Prochlorococcus sp. are identified using chromatographic/spectroscopic techniques and quantified using HPLC-DAD. In the present study, β-apo-8′-carotenal was used as internal standard. Identification of carotenoids was carried out by comparing the retention time, absorption spectra, and mass spectra of unknown peaks with reference standards. All-trans-lutein was found to be the major carotenoid in this cyanobacterium, and, therefore, algal productivity and the potential for lutein accumulation were analyzed as a function of different nitrogen sources such as nitrate, nitrite, ammonia, and urea for cultivation. Among them, urea clearly led to the best lutein accumulation. According to the experimental evidence, lutein increased from 2.54 to 3.34 mg g−1 in the cyanobacteria when urea was used as the nitrogen source. © 2016, Springer Science+Business Media Dordrecht.Article Citation - WoS: 8Hydrogen Sulfide Determination by Solid Surface Luminescence(Springer Verlag, 1996) Eroğlu, Ahmet Emin; Volkan, Mürvet; Bayramlı, Erdal; Ataman, O. Yavuz; Mark, Harry B.In the analytical system suggested, atmospheric hydrogen sulfide reacts with the surface of a filter paper treated with aqueous cadmium chloride and yields a luminescent species whose intensity can be correlated with the analyte concentration in ambient air. It was shown that the luminescent species are CdS solid particles which were formed in a well defined size. The paper luminescence was also tried on polymeric surfaces; polyethyleneoxide, polyvinyl alcohol, ethylcellulose and carboxymethylcellulose were found to give a similar luminescence signal. The system can be used on the tip of an optical fiber for an irreversible, cumulative type of analytical device for hydrogen sulfide determination. The 3s detection limit for the paper luminescence detection system was 7.8 ppb H2S.