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Öğe DES-based vortex-assisted liquid-liquid microextraction procedure developed for the determination of paraben preservatives in mouthwashes(Elsevier, 2022) Dalmaz, Aslıhan; Ozak, Sezen SivrikayaA green deep eutectic solvent-based vortex-assisted liquid-liquid microextraction (DES-VALLME) procedure for the determination of parabens in mouthwashes was developed. Deep eutectic solvents formed by combining DLmenthol and decanoic acid in different mol ratios were prepared, the highest extraction recovery was obtained with DES consisting of 4:1 M ratio, and this DES was used as an extraction solvent for paraben determination in mouthwashes. The effect of parameters such as solution pH, mol ratio of DES composition, DES volume, vortex and centrifugation time and sample volume were examined. Optimum working conditions of the study; 400 mu L DES, 3 min. vortex time, 5 min. centrifugation time, 5 mL sample volume were determined. The detection limit was in the range of 4.6-6.1 mu g L-1, while the RSDs values were in the range of 0.70-1.41% in intraday and 1.27-2.41% in interday. The method in the study was successfully applied for the determination of methyl, ethyl, propyl and butyl paraben in 10 different mouthwashes obtained from cosmetic stores..Öğe Development of clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction method for the determination of Rhodamine B in cosmetic products(Elsevier, 2022) Dalmaz, Aslıhan; Ozak, Sezen SivrikayaGreen synthesis of clinoptilolite zeolite/Fe3O4 nanocomposite (MZNC) was carried out using Laurus Nobilis L. leaf extract. Characterization of this MZNC was performed using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and Vibrating Sample Magnetometer. According to the VSM analysis results, the saturation magnetization of 23 emu/g and coercivity of 23.5 Oe indicate that the synthesized magnetic nanocomposite is superparamagnetic. A new ultrasonic assisted clinoptilolite zeolite-coated magnetic nanocomposite-based solid phase microextraction (MZNC-SPME) method com-bined with high performance liquid chromatography was developed for the extraction and determination of Rhodamine B. The preconcentration factor for the MZNC-SPME method was found to be 40 under opti-mal conditions. Under optimal conditions, the linear range, correlation coefficient (R 2 ), limit of detection (LOD), and intra-and interday relative standard deviation (RSD) were found to be 1.0 0-10 0.0 0 ng mL -1, 0.9995, 0.16 ng mL(-1), 1.89% and 2.49%, respectively. The developed method was successfully performed to determine Rhodamine B in 6 different cosmetic samples. 6 ions and 5 different dyes were added to the sample solution to show the selectivity of the method. The obtained results show that the determination of Rhodamine B is possible in the presence of these ions and dyes. In order to determine the accuracy of the MZNC-SPME method, two different concentrations of Rhodamine B concentration in cosmetic sam-ples were added as 10 and 50 ng mL -1. Extraction recoveries were found in the range of 92.03-101.52% and these results are quite satisfactory. It is seen that the developed method for the extraction and deter-mination of Rhodamine B from cosmetic samples is applicable due to the easy synthesis of the sorbent and the short, simple, environmentally friendly and low cost of the method.(c) 2022 Elsevier B.V. All rights reserved.Öğe Green and simple microextraction method based on deep eutectic solvent-assisted smartphone digital imaging colorimetry (SDIC) for Rhodamine B analysis in food products(Springer Heidelberg, 2025) Tezcan, Buse; Dalmaz, Aslihan; Ozak, Sezen SivrikayaThis study employed a deep eutectic solvent-based liquid-liquid microextraction method and smartphone digital image colorimetry to detect and quantify Rhodamine B in foods. The deep eutectic solvent, a green solvent, was prepared by mixing tetrabutylammonium bromide and octanol in a 1:2 ratio. It was observed that Rhodamine B dyestuff readily transitioned to the DES phase, eliminating the need for additional reagents. The impact of various parameters, including DES type, molar ratio, volume, solution pH, ultrasonic time, centrifugation time, and sample volume, on extraction efficiency was examined, and the most effective conditions were determined. Additionally, the diameter of the prepared colorimetric box and the distance between the detector and the sample were investigated, leading to the identification of optimal conditions. The developed method's limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.0054 mu g/mL and 0.018 mu g/mL, respectively, for the measurements taken using seven parallel blank solutions at 554 nm. The relative standard deviations intraday and interday were 1.29% and 2.03%, respectively. The calibration graph demonstrated good linearity, with a coefficient of determination of 0.9996. The developed method's intraday and interday relative standard deviation values were 2.03% and 1.29%, respectively. Rhodamine B was detected in food samples using the developed method, obtaining extraction recoveries ranging from 95.16 to 103.88%.Öğe Green synthesis of ZnO nanoparticles using Laurus nobilis L. extract and investigation of corrosion inhibition properties of DES-based nanofluids(Springer, 2024) Dalmaz, Aslihan; Kasimfirtina, Eren; Ozak, Sezen SivrikayaIn this study, new nanofluids based on four different deep eutectic solvents consisting of acetic acid and ethylene glycol as hydrogen bond acceptors, choline chloride, and water as hydrogen bond donor were prepared and these deep eutectic solvents, ZnO used to influence the corrosion of nanoparticles. The study's originality is that for the first time in this study, ZnO nanoparticles obtained with the help of the green material deep eutectic solvent and the extract of Laurus nobilis L. leaves were used effectively in the corrosion study. As a result of the corrosion studies, the best corrosion prevention efficiency was determined in the nanofluid prepared by adding 0.015% by weight ZnO nanoparticles. According to the XRD analysis results, the synthesized ZnO nanoparticles are formed in a hexagonal structure. When the SEM images of ZnO nanoparticles were examined, it was seen that the obtained structure was homogeneous, and the dimensions of the nanoparticles varied between 12 and 33 nm. The thermal stability of ZnO nanoparticles was proven from the TGA curve, where only a 2% weight loss was observed. ZnO nanoparticles did not undergo any degradation up to 1000(degrees)C.Öğe Hydrophilic deep eutectic solvent based microextraction procedure for the determination of four paraben preservatives in vitamin D for babies: A green approach(Elsevier, 2023) Akmes, Ali; Dalmaz, Aslihan; Ozak, Sezen SivrikayaIn this study, an easily available, sensitive, and fast hydrophilic deep eutectic solvent-liquid phase microextraction method developed using deep eutectic solvent (DES) as a green solvent for the determination and microextraction of paraben (methyl, ethyl, propyl, and butyl) preservatives in vitamin D for babies. The highest yield for extraction recovery was obtained using DES consisting of a 1:4 M ratio of choline chloride and acetic acid. Moreover, various optimization parameters such as DES volume, DES type, sample volume, and centrifugation time were investigated in order to develop a real sample specific microextraction method. Relative standard deviation values were 0.92%-2.87%, the detection limit was 0.194-0.254 & mu;g/mL, and extraction recovery values were between 87.40% and 102.98%. The method developed in this study was successfully applied to 5 different babies in vitamin D for babies obtained from pharmacies for the determination of methyl, ethyl, propyl, and butylparaben. As far as we know, it is the first study conducted both in terms of the determination of paraben preservatives in vitamin D for babies and in terms of the fact that DES used in this study is used for the first time in vitamin D for babies.Öğe Rapid and eco-friendly microextraction procedure based on green hydrophobic deep eutectic solvent for simultaneous determination of five sex hormones from cosmetic samples(Elsevier, 2024) Dalmaz, Aslihan; Ozak, Sezen SivrikayaHormones, which are among the endocrine disruptors, are used in many fields and their use in cosmetic products has recently attracted considerable attention. Despite the negative health consequences, there is no detailed guidance that limits the use of these endocrine disruptors. This study aimed to develop a green hydrophobic deep eutectic solvent (HDES)-based microextraction method for the detection and quantification of sex hormones (progesterone, (3-estradiol, estrone, ethinylestradiol, and testosterone) in different cosmetic products. The best value for extraction recovery was obtained by using DL-menthol and dodecanoic acid as green HDES in a 4:1 mole ratio. Optimization parameters such as HDES volume, pH, sample volume, centrifugation time, mixing type, and mixing time were investigated for cosmetic samples to be used as real samples. Furthermore, the extraction recovery values ranged from 85.7 % to 101.3 % and the detection limit was between 2.33-3.30 ng mL- 1. Additionally, three different greenness methods, namely ComplexGAPI, AGREEprep, and BAGI, were used to evaluate how green the proposed method is in this study. The microextraction procedure developed in this study was successfully applied to five different cosmetic samples that will be used as real samples to detect and determine sex hormones.Öğe Simultaneous microextraction of Brilliant Blue FCF, Malachite Green, and Rhodamine B in children's play materials: Assessment of greenness approach(Pergamon-Elsevier Science Ltd, 2025) Dalmaz, Aslihan; Ozak, Sezen SivrikayaThe types, quantities, and permissible limits of dyestuffs used in the toy industry are susceptible since the relevant audience is children. For this reason, the dyestuffs used in children's play materials are one of the crucial issues to be emphasized. Rhodamine B, Brilliant Blue FCF, and Malachite Green are some of the most commonly used dyestuffs, and they are also included in our study. In addition to making play materials fun for children, it is vital to determine the amount of the dye in the play material to know the damage it will cause. For this purpose, an ultrasonically assisted, rapid, and highly sensitive green deep eutectic solvent-based microextraction method was developed to detect three synthetic dyes in different children's play materials. Extraction recoveries were between 92.8 and 103.2% under optimum conditions. The method was promising when the results obtained were compared with other studies. When additional recovery studies were carried out on different children's play materials, Rhodamine B in pink-coloured playdough and finger paint, Brilliant Blue FCF in blue-coloured playdough, finger paint, and watercolour paint, and Malachite green dyestuffs in finger paint and crayon were detected. In addition, this study is noteworthy as it is the first study in which simultaneous determination of three dyestuffs by high-performance liquid chromatography method was carried out.Öğe Spectrophotometric determination for green hydrophobic deep eutectic solvent-based microextraction of Brilliant Blue FCF (E133) from beverages(Elsevier, 2024) Olgun, Mahmut; Ozak, Sezen Sivrikaya; Dalmaz, AslihanIn this study, a simple, sensitive, and rapid method called green hydrophobic deep eutectic solvent-based liquid- liquid microextraction was developed to extract Brilliant Blue FCF dye from beverages. This method utilizes hydrophobic DES obtained by forming tetrabutylammonium bromide and 1-octanol in a 1:5 ratio as green extraction solvent. The transition of Brilliant Blue FCF to the DES phase occurred on its own, without the need for any reagents such as added salt or tetrahydrofuran. Several crucial factors were tried to get the best extraction efficiency, including species, DES volume and molar ratio, solution pH, ultrasonication, and centrifugation time. Under optimum conditions, extraction recoveries were achieved in the range of 95.1-101.3 % with the method developed for Brilliant Blue FCF. The detection and determination limits were observed to be 4.1 mu g L-1 and 12.1 mu g L-1, respectively. In addition, the relative standard deviation values for the method's accuracy were found to be 2.23 % and 3.48 % within and between days, respectively. It has been established that the developed method is highly environmentally friendly thanks to the application of the Analytical GREENness (AGREE) and Green Analytical Procedure Index (GAPI) tools. This study shows that DES applications can be carried out without the use of emulsifiers and dispersants by prioritizing the use of hydrophobic DES compounds as environmentally friendly and green extraction solvents in food samples.Öğe Supramolecular solvent based microextraction for green and selective spectrophotometric determination of Rhodamine B in makeup products(Taylor & Francis Ltd, 2025) Yildiz, Ilayda Nur; Dalmaz, Aslihan; Ozak, Sezen SivrikayaMany dyes are used for various purposes in different industries and are often complex organic compounds. Many analytical techniques are inadequate to determine the concentrations of these dyes. Additionally, prolonged exposure to dyes can lead to serious health issues. For these reasons, dye quantification has become more important, and the pre-concentration method has been developed and used to determine the dye concentration. In this study, a supramolecular solvent-based liquid-phase microextraction method was developed and utilized for the enrichment and UV-Vis spectroscopic determination of Rhodamine B dye added to various cosmetic samples. Moreover, the effects of the parameters determining the supramolecular solvent, pH, centrifugation time, sample volume, and ultrasonic bath time were optimized. The advantages of the developed method compared to other methods are that the extraction time is very short, solvents and chemicals do not require high cost, and do not require the use of large volumes. Thus, this method has been shown to be a useful, reliable, fast, and valid method for the determination of Rhodamine and similar dyes used in cosmetics. Under optimum conditions, the detection limit was 1.31 mu g L-1, the linear range was 5-1000 mu g L-1, the correlation coefficient was 0.9994, the intra-day relative standard deviation was 2.12 mu g L-1, and the inter-day relative standard deviation was 3.30 mu g L-1. The microextraction method was successfully applied to determine Rhodamine B dyestuff in different cosmetic samples such as lipstick, nail polish, eyebrow fixative, blush, and peeling.Öğe Ultrasound-assisted hydrophobic deep eutectic solvent based solid-liquid microextraction of Sudan dyes in spice samples(Pergamon-Elsevier Science Ltd, 2020) Ozak, Sezen Sivrikaya; Yilmaz, YunusAn environmentally friendly, simple method was carried out with the help of an ultrasonic assisted solid-liquid microextraction technique using a new deep eutectic solvent (DES) for the extraction and determination of Sudan dyes (I-IV) in spice samples. In this method, parameters affecting the optimization were researched and optimized such as DES composition, DES volume, ultrasonic time, temperature and, centrifuge time. The analytical performance of the developed method was quite satisfactory, the R-2 values were higher than 0.9989, and the limits of quantification were <1.17 mu g g(-1). Two different concentrations (10-50 mu g g(-1)) were spiked to Chili peppers, paprika, cumin and sumac spices for the applicability and accuracy of the developed microextraction method. Some of these spices were found to contain Sudan I and IV dyes. The recovery values for spiked samples were found to be between 85.55% and 99.29% and relative standard deviations were found to be <3.17% when using a 10 mu g g(-1) Sudan dyes concentration. The results showed that the developed method can be successfully applied for extraction and determination of Sudan dyes in spice samples. (C) 2020 Elsevier B.V. All rights reserved.
