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Accurate and sensitive determination of mefenpyr-diethyl in barley, oat and corn silk matrices by gas chromatography – flame ionization detector (GC–FID)
(Zonguldak Bülent Ecevit University, 2024) Serbest, Hakan
Pesticides are frequently utilized in the cultivation of agricultural products for human consumption to prevent / minimize the detrimental effects caused by pests and to keep the yield at the desired levels at harvest time. Besides the benefits of pesticides, unconscious use of pesticides causes the occurrence of different diseases. Monitoring the levels of pesticide residues is of vital importance for the environment, human, and other living organisms. In the present study, an analytical method was reported for the determination of mefenpyr-diethyl (MFD) as a member of the herbicide group by gas chromatography flame ionization detector (GC-FID) system with high accuracy and sensitivity. An in-column temperature program was established to effectively separate the analyte, and MFD was determined at a retention time of 5.2 min. The limit of detection (LOD), the limit of quantitation (LOQ), and the linear working range were found to be 0.01 mg/L, 0.04 mg/L, and 0.07-29.7 mg/L, respectively. The applicability of the determination method was investigated by recovery studies with barley, oat, and corn silk matrices. No analytical signal was recorded for MFD in blank samples of all three species. Recovery results close to 100% showed that MFD could be determined with high accuracy in barley, oat, and corn silk matrices.
Determination of cobalt in chamomile tea samples at trace levels by flame atomic absorption spectrophotometry after poly(vinyl alcohol)-magnetic hydrogel based dispersive solid phase extraction
(The Royal Society of Chemistry, 2023) Karlıdağ, Nazime Ebrar; Demirel, Rabia; Serbest, Hakan; Turak, Fatma; Bakırdere, Sezgin
In this study, an analytical strategy was proposed for the determination of cobalt at trace levels by using a flame atomic absorption spectrophotometry (FAAS) system after magnetic hydrogel based dispersive solid phase extraction (MH-DSPE). Poly(vinyl alcohol) based magnetic hydrogels (PVA-MH) were synthesized easily, quickly, and cost effectively in the laboratory and used as an adsorbent material in the microextraction process. Under the optimum experimental conditions, the limit of detection (LOD) and limit of quantitation (LOQ) values were recorded as 4.2 and 14.1 mg L−1 , respectively. To investigate the matrix effects on the analyte signal, spike experiments were performed using chamomile tea extracts and good recovery results were obtained between 85.7 and 113.8%. A 57.8-fold improvement was achieved in the detection power compared to that of a conventional FAAS system. The results obtained throughout all experimental studies demonstrated the applicability in addition to the accuracy of the method for the quantification of trace levels of cobalt with high accuracy in a chamomile tea matrix.
Determination of resmethrin in corn silk matrix by gas chromatography-flame ionization detector (GC-FID)
(Sakarya Üniversitesi, 2022) Serbest, Hakan
The use of pesticides provides benefits such as growing food products necessary for life, sustainability of production efficiency and prevention of diseases caused by pests. However, these benefits can turn into negative effects for humans and other living organisms with the use of pesticides in inappropriate doses and application methods. In this study, it was aimed to determine resmethrin, which belongs to the insecticide class, by gas chromatography-flame ionization detector (GC-FID) method. Hence, a suitable temperature program was utilized to determine resmethrin at a certain retention time. Limit of detection (LOD) and limit of quantification (LOQ) values were recorded as 0.02 and 0.08 mg/L under the proposed conditions, respectively. After corn silk sample was extracted using acetonitrile, analytical measurements were carried out to investigate the presence of resmethrin. There was no analytical signal detected that belonged to resmethrin in the analyzed sample. Recovery experiments were performed using external calibration method with spiked samples at three different concentrations and good percent recovery results were obtained between 93 and 97%.
Determination of rhodium in soil by DispersiveSolid-Phase Extraction (DSPE) with manganese ferrite nanoparticles and Flame Atomic Absorption Spectrometry(FAAS)
(Taylor & Francis, 2024) Serbest, Hakan
Manganese ferrite (MnFe2O4) nanoparticles-assisted dispersive solid-phase extraction (MF-DSPE) was developed for the determination ofrhodium (Rh) in soil samples at low levels with good accuracy andprecision by flame atomic absorption spectrometry (FAAS). The syn-thesis of MnFe2O4nanoparticles was carried out in a microwave sys-tem by a rapid procedure. The pH, buffer volume, sorbent mass,sample volume, eluent volume/concentration, and mixing time wereidentified with univariate optimization. Under the optimal conditions,the limits of detection (LOD) and quantitation (LOQ) were 4.4 and14.7mgL 1, respectively. The sensitivity was improved by 121.9-foldbased upon comparison of the limits of detection with and withoutpreconcentration. The applicability was investigated by spiking rho-dium into soil extracts, and good recovery results between 91.2%and 122.2% were achieved using matrix matching calibration. Theresults showed that MF-DSPE-FAAS determines low levels of rhodiumin soil with good accuracy and precision.
Development an effective adsorptive treatment strategy for the removal of cadmium from textile wastewater by CuBi2O4@Fe3O4 nanocomposites
(Taylor & Francis, 2024) Büyük, Muhammed Ali; Serbest, Hakan; Dalgıç Bozyiğit, Gamze; Bakırdere, Sezgin
In this study, copper-bismuth oxide/iron oxide (CuBi2O4@Fe3O4) nanocomposites were pre-pared by microwave-assisted synthesis and used as adsorbents for the adsorptive removalof cadmium from textile wastewater. The pH/volume of buffer solution, mixing type/periodand adsorbent dosage were optimized univariately to enhance the removal efficiency of theadsorbent and determined as 1.5 mL of pH 8.0 buffer solution, vortexing for 60s, and 30 mgof CuBi2O4@Fe3O4 nanocomposite material. Following the determination of the optimumparameters, equilibrium adsorption studies were performed at five different initial concentra-tions of cadmium within the range of 0.50 − 10 mg L−1 in textile wastewater. A matrix-matching calibration strategy was utilized for the accurate and precise quantification of cad-mium in the wastewater matrix with a R2 value of 0.9961. The percent removal efficiencieswere calculated within the range of 77.2 − 81.5% for the adsorptive removal of cadmiumions from textile wastewater in the equilibrium adsorption experiments. Furthermore, theLangmuir, Freundlich, and Sips adsorption isotherm models were employed for modelingthe equilibrium data, and the results showed that all the models fitted well with the experi-mental data with R2 values higher than 0.99. The simple and efficient batch adsorption pro-cess developed was successfully utilized to remove cadmium ions from textile wastewater.
Development of an analytical method for the determinationof trace lead in lake water samples by flame atomicabsorption spectrophotometry after vortex assisted-stearicacid coated magnetic nanoparticle based extraction
(Wiley, 2023) Serbest, Hakan
In the present study, a method is proposed for the determination of lead at trace levels by slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) after preconcentration with stearic acid coated magnetic nanoparticle-based dispersive solid phase extraction (SA-MNP-DSPE). The slotted quartz tube (SQT) is used to enhance the analyte atom residence time in the light path. Stearic acid coated magnetic iron oxide (Fe3O4) nanoparticles, which can be easily collected with an external magnet, are used as adsorbent in the extraction process. The limit of detection (LOD) and the limit of quantitation (LOQ) values of the proposed method are obtained as 0.90 and 2.9 mu g L-1, respectively. The method allows high repeatability in a wide linear range between 5.0 and 250 mu g L-1, and the relative standard deviation for six replicates is 5.8%. The detection power is enhanced by about 77-fold compared to the regular flame atomic absorption spectrophotometry (FAAS) system. The method is validated by recovery experiments to four different lake water samples. After the spiking tests, good recovery results are calculated between 97% and 106%. These results show that lead can be detected at low levels in lake water samples with high sensitivity, accuracy, and precision.
Development of an analytical strategy for the determination of trace lead in hibiscus tea extract by double slotted quartz tube assisted flame atomic absorption spectrometry after manganese ferrite based dispersive solid phase extraction
(Elsevier, 2023) Karaman, Devrim Nur; Serbest, Hakan; Bahçivan, Aleyna; Polat Korkunç, Ümmügülsüm; Bakırdere, Sezgin
In this study, a manganese ferrite (MnFe2O4) based dispersive solid phase extraction method (MF-DSPE) was proposed for the determination of lead (Pb) ions in hibiscus tea by double slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS). The MnFe2O4 nanoparticles used as sorbent were produced in high yields using a green and friendly microwave synthesis procedure. The limit of detection (LOD) was found to be 14.2 µg/L under the optimal conditions. Recovery experiments were performed to assess the applicability of the developed method using hibiscus tea as test sample matrix. High recovery results were obtained by applying the matrix matching calibration method. Thanks to the developed MF-DSPE-SQT-FAAS method, the detection sensitivity for lead was improved by about 108-folds according to the comparison of the slopes of the calibration plots of the FAAS and MF-DSPE-SQT-FAAS systems.
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.
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.
Plastic sieve equipped two-syringe assisted magnetic colloidal gel for dispersive solid-phase extraction of manganese in tea samples
(Elsevier, 2022) Aydın, Efe Sinan; Zaman, ‪Buse Tuğba; Serbest, Hakan; Kapukıran, Fatih; Turak, Fatma; Bakırdere, Sezgin
In this study, a simple and effective analytical method was described for the determination of manganese in a spectrometric system. For this purpose, a plastic sieve fitted between two syringes was used as a dispersive solid phase extraction tool. The extraction of manganese was performed by using a magnetic colloidal gel (MCG), which was formed by mixing cobalt magnetic nanoparticle (Co-MNP) and deep eutectic solvent. All experimental parameters of the method including Co-MNP amount in MCG, MCG volume, cycle number for pressurized mixing in the two-syringe system and eluent type/volume in the desorption step were carefully evaluated in order to find the best experimental conditions for efficient extraction/preconcentration of manganese. The detection limit was calculated as 4.0 ng/mL for manganese extracted by 150 µL of MCG from 8.0 mL of aqueous solution at pH 10 with 8 cycles of pressurized mixing. In order to validate the applicability and the accuracy of the developed system, the optimum conditions were applied to jasmine tea samples. The tea samples were analyzed using the standard addition method and the manganese the manganese content were found in the range of 133 – 245 ng/mL. The obtained results showed that the developed method is applicable, accurate and feasible for the determination of manganese at trace levels.
Trace cadmium determination in lake water matrix by flame atomic absorption spectrometry after manganese ferrite magnetic nanoparticles-based dispersive solid phase extraction
(Wiley, 2023) Karaman, Devrim Nur; Serbest, Hakan; Kılınç, Yağmur; Demirel, Rabia; Bakırdere, Sezgin
In this study, manganese ferrite magnetic nanoparticles-based dispersive solid phase extraction (MF-MNP-DSPE) was developed for cadmium determination at trace level by flame atomic absorption spectrometry (FAAS). Manganese ferrite-based magnetic nanoparticles were synthesized to be used as solid phase extraction sorbent. All the analytical conditions were optimized by univariate optimization approach to achieve high enrichment factors. Under the optimum conditions, limit of detection (LOD) and quantification (LOQ) values of the developed method were recorded as 1.3 and 4.3 µg L−1, respectively. Approximately 135-fold improvement in the detection power by the MF-MNP-DSPE-FAAS system was recorded over the traditional FAAS system based on LOD comparison. Recovery experiments were performed to test the applicability/accuracy of the developed method with lake water spiked at different concentrations. Percent recovery values were obtained between 87% and 112% by employing the matrix matching calibration strategy and this showed that the developed method is applicable for the determination of cadmium in lake water samples with high accuracy and precision.

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