Showing papers by "Sezgin Bakırdere published in 2022"

Polystyrene-coated magnetic nanoparticles based dispersive solid phase extraction for the determination of cadmium in cigarette ash prior to slotted quartz tube flame atomic absorption spectrometry system

Abstract: A sensitive, accurate and simple analytical method was developed to determine cadmium by slotted quartz tube-flame atomic absorption spectrometry after preconcentration/extraction with polystyrene coated magnetic nanoparticles based dispersive solid phase extraction. The surface of Fe3O4 based magnetic nanoparticles was modified with polystyrene to yield higher selectivity and sensitivity in adsorption efficiency of cadmium. The nanoparticles were dispersed into the aqueous solution to extract/separate cadmium. Significant parameters of the method including magnetic nanoparticle amount, mixing effect, effect of ionic strength, eluent concentration and sonication period were optimized to achieve optimal conditions for the analyte. The limit of detection and quantification values of the developed method were found to be 0.62 and 2.1 ng/mL, respectively. Under the optimum conditions, enhancement of the detection power for cadmium were calculated as 102 folds for the developed method. The developed method was then applied to cigarette ash to test its accuracy and applicability. Total cadmium was found to be between 402 and 450 ng/g in the ashes of different cigarette brands commercially available in Turkey. The accuracy of quantifying cadmium in the complex ash samples was enhanced by using the matrix matching calibration strategy. The developed method provides sensitive and selective determination of cadmium at ng/mL levels even at complex cigarette ash samples. High percent recovery results (90-102%) were obtained from spiked real samples.

Polystyrene‐Coated Magnetite Nanoparticles Based Dispersive Micro‐Solid Phase Extraction of Active Pharmaceutical Ingredients of Antidepressant Drugs and Determination by GC‐MS

Abstract: A dispersive micro-solid phase extraction (D-μ-SPE) method based on polystyrene coated magnetic nanoparticles (PS@MNPs) was used to preconcentrate the active ingredients of three antidepressant drugs from aqueous solution to be determined by gas chromatography mass spectrometry. Eight prominent parameters of the D-μ-SPE method were optimized univariately to boost the recovery and extraction efficiency of the analytes. The three analytes recorded very low detection limits between 0.40 and 0.60 ng/mL, and the dynamic range was broad with high linearity. Medical wastewater was selected as test sample to evaluate the method's applicability and accuracy, and the percent recovery results obtained ranged between 90 and 98 % for two different spike concentrations. The proximity of the recovery results to 100 % and the low standard deviations validated the developed method's accuracy and precision, respectively.

Polystyrene-coated magnetic nanoparticles based dispersive solid phase extraction for the determination of cadmium in cigarette ash prior to slotted quartz tube flame atomic absorption spectrometry system

Abstract: A sensitive, accurate and simple analytical method was developed to determine cadmium by slotted quartz tube-flame atomic absorption spectrometry after preconcentration/extraction with polystyrene coated magnetic nanoparticles based dispersive solid phase extraction. The surface of Fe3O4 based magnetic nanoparticles was modified with polystyrene to yield higher selectivity and sensitivity in adsorption efficiency of cadmium. The nanoparticles were dispersed into the aqueous solution to extract/separate cadmium. Significant parameters of the method including magnetic nanoparticle amount, mixing effect, effect of ionic strength, eluent concentration and sonication period were optimized to achieve optimal conditions for the analyte. The limit of detection and quantification values of the developed method were found to be 0.62 and 2.1 ng/mL, respectively. Under the optimum conditions, enhancement of the detection power for cadmium were calculated as 102 folds for the developed method. The developed method was then applied to cigarette ash to test its accuracy and applicability. Total cadmium was found to be between 402 and 450 ng/g in the ashes of different cigarette brands commercially available in Turkey. The accuracy of quantifying cadmium in the complex ash samples was enhanced by using the matrix matching calibration strategy. The developed method provides sensitive and selective determination of cadmium at ng/mL levels even at complex cigarette ash samples. High percent recovery results (90-102%) were obtained from spiked real samples.

Novel Salicylic Acid Modified Magnetic Nanoparticles Based Ligandless Extraction for the Accurate Determination of Bismuth in Urine Samples by Flame Atomic Absorption Spectrophotometry

Abstract: Abstract An efficient, novel, rapid and green ligandless dispersive solid phase extraction method (LDSPE) based on salicylic acid modified magnetic iron nanoparticles (SA-MNPs) was combined with slotted quartz tube integrated flame atomic absorption spectrometry (SQT-FAAS) for sensitive bismuth determination in human urine. For this purpose, SA-MNPs were synthesized via a simple procedure and used as sorbent for the effective extraction/preconcentration of bismuth from the aqueous samples. This is the first report in the literature in which this analytical combination (SA-MNPs-LDSPE-SQT-FAAS) was utilized for the determination of bismuth. Under the determined optimum conditions, the linear range was between 20 and 250 µg L−1. The limit of detection (LOD) and limit of quantification (LOQ) values for bismuth were 6.0 and 21.0 µg L−1, respectively. A 94-fold enhancement in the detection power of FAAS was achieved using the SA-MNPs-LDSPE-SQT-FAAS method. To examine the method’s accuracy and applicability, the optimal procedure was applied to spiked human urine. Satisfactory recoveries from 95% to 101% were obtained with matrix matching, indicating that the developed method can be used for bismuth determination in biological samples.

Magnetic Nanoparticle-Based Dispersive Solid-Phase Microextraction of Three UV Blockers Prior to Their Determination by HPLC-DAD

Abstract: The need for proper handling of environmental samples is significant, owing to their environmental effects on both humans and animals, as well as their immediate surroundings. In the current study, magnetic nanoparticle-based dispersive solid-phase microextraction was combined with high-performance liquid chromatography using a diode array as the detector (HPLC-DAD) for both the separation and determination of three different UV blockers, namely octocrylene, ethylhexyl methoxycinnamate, and avobenzone. The optimum conditions for the extraction were found to be as follows: Stearic acid magnetic nanoparticles (20 mg) as the sorbent, acetonitrile (100 µL) as the eluent, as well as a sample pH of 2.50, adsorption and desorption time of 1.0 min, with a 3.0 mL sample volume. The limits of detection were as low as 0.05 µg mL−1. The coefficient of determination (R2) was above 0.9950, while the percentages of relative recoveries (%RR) were between 81.2 and 112% for the three UV blockers from the environmental water samples and sunscreen products.

A simple and efficient derivatization strategy combined with switchable solvent liquid-liquid microextraction-hydroxychloroquine methyl acetate-d3 based quadruple isotope dilution-gas chromatography-mass spectrometry for the determination of hydroxychloroquine sulfate in biological fluids.

Abstract: RATIONALE In this study, a derivatization-switchable solvent liquid-liquid microextraction-quadruple isotope dilution-gas chromatography-mass spectrometry (D-SS-LLME-ID4 -GC-MS) method was presented for the determination of hydroxychloroquine sulfate in human biofluids. METHODS While mixing type/period and concentration of NaOH were optimized via univariate optimization approach, multivariate optimization approach was used to determine optimum values for relatively more important parameters such as volumes of derivatization agent (acetic anhydride), NaOH and switchable solvent. RESULTS Under the optimum experimental conditions, limit of detection (LOD) and limit of quantification (LOQ) were calculated as 0.03 mg/kg and 0.09 mg/kg (mass based), respectively. An isotopically labelled material (hydroxychloroquine methyl acetate-d3 ) was firstly synthesized to be used in quadruple isotope dilution (ID4 ) experiments which have highly accurate and precise recovery results. After the application of D-SS-LLME- ID4 , superior percent recovery results were recorded as 99.9 ± 1.6 - 101.3 ± 1.2 for human serum, 99.9 ± 1.7 - 99.8 ± 1.8 for urine and 99.6 ± 1.5 - 101.0 ± 1.1 for saliva samples. CONCLUSION Developed D-SS-LLME-ID4 -GC-MS method compensates the complicated matrix effects of human biofluids and provides highly accurate quantification of the analyte with precise results.

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.

Abstract: 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 μg 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.

Trace Determination of Rhodium in Coating Wastewater by Vortex Assisted Magnetic Nanoparticle Based Solid Phase Microextraction (MNP-SPME) Combined with Slotted Quartz Tube–Flame Atomic Absorption Spectrometry (SQT-FAAS) with Matrix Matching Calibration

Abstract: Abstract A magnetic nanoparticle based solid phase microextraction method (MNP-SPME) was developed for the extraction/preconcentration of rhodium prior to determination by slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS). The extraction efficiency was enhanced by the binary MNPs (uncoated MNPs and amidosulfonic acid coated MNPs). The parameters affecting rhodium extraction such as the pH and volume of buffer solution, mixing type/period after the addition MNPs and sample volume were optimized by univariate optimization. Box-Behnken design with five center points was also used as a multivariate approach for the determination of the optimum values of the MNP mass and percentages and eluent volume. Under the optimum conditions, the limits of detection and quantitation were 0.3 and 1.1 µg L−1. In order to characterize the applicability/accuracy of the method, spiking experiments were performed in metal coating wastewater. Recoveries were between 95.5% and 102.9% using matrix matching calibration. The developed method achieved a 129.1-fold enhancement in detection power compared to FAAS. The recovery results demonstrated the accuracy of the developed strategy for the determination of rhodium in complex matrices.

Quantification of Seventeen Elements in Musical Drumheads and the Extractability of Arsenic, Lead and Chromium with Determination by Inductively Coupled Plasma – Mass Spectrometry (ICP-MS)

Abstract: Abstract Seventeen elements were determined in various drumheads in order to establish the elemental composition of the samples. Eleven samples were analyzed by inductively coupled plasma – mass spectrometry (ICP-MS) and the concentrations of seventeen metals (Be, Na, Mg, Ni, Al, Pb, Fe, As, Cr, Co, Cu, Se, Cd, Ru, Pd, Sn, and Sb) were determined. Migration experiments using artificial sweat were performed for three elements (As, Cr, Pb) to evaluate their extractable fractions. Exposure via dermal route to heavy metals generally receives less attention than exposure via inhalation or oral pathways. Metal determination may be beneficial to the polymer industry since heavy metals in polymers may contribute to problems during the manufacturing process. Characterization studies were performed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Be, Se, Ru, and Pd were not detected in any samples. The concentrations of the metals were from 72.84 to 354.9 µg/g for Sb, 357.9 to 15,750 ng/g for Pb, 0.28 to 121.1 µg/g for As, 101.9 to 501.6 ng/g for Cu, 383.1 to 1536 ng/g for Ni, 11.46 to 124.0 µg/g for Fe, 319.7 to 1046 ng/g for Cr, 213.2 to 1035 µg/g for Al, 1.74 to 1213 µg/g for Mg, and 118.5 to 892.5 µg/g for Na.

Stearic Acid Functionalized Iron Nanoparticle Based Magnetic Solid-Phase Extraction (MSPE) for the Determination of Oxadiazon in Purslane by High-Performance Liquid Chromatography (HPLC)

Abstract: Abstract An accurate, simple, and sensitive method was developed for the determination of the herbicide oxadiazon in purslane. The method was based on magnetic solid phase extraction (MSPE) using stearic acid modified iron oxide nanoparticles (Fe3O4@SA) as the adsorbent for preconcentration, followed by the reverse phase high performance liquid chromatography (HPLC) determination of oxadiazon. The MSPE method was optimized using the univariate approach of optimization, where one parameter was tested at different variables and the other parameters were held constant. Using the optimum conditions, the oxadiazon limits of detection and quantification (LOD and LOQ) were 0.29 and 1.0 ng mL−1. The calibration plot of the method was linear across a broad dynamic range from 1.0 to 1000 ng mL−1 with a coefficient of determination equal to 0.9988. The accuracy and applicability of the method was validated by performing spike recovery experiments with purslane samples. The matrix matching calibration strategy was used to mitigate interferences from the sample to attain recovery values between 90 and 110%. The high recoveries and low standard deviations (<10%) verified the accuracy and precision of the developed protocol.

Determination of levetiracetam by GC-MS and effects of storage conditions and gastric digestive systems on drug samples.

Abstract: Background: Epilepsy is a neurologic condition that is occurs globally and is associated with various degrees of seizures. Levetiracetam is an approved drug that is commonly used to treat seizures in juvenile epileptic patients. Accurate quantification of the drug's active compound and determining its stability in the stomach after oral administration are important tasks that must be performed. Results & methodology: Levetiracetam was extracted from drug samples and quantified by gas chromatography mass spectrometry using calibration standards. Stability of levetiracetam was studied under various storage conditions and in simulated gastric conditions. The calibration plot determined for levetiracetam showed good linearity with a coefficient of determination value of 0.9991. The limits of detection and quantification were found to be 0.004 and 0.014 μg·ml-1, respectively. The structural integrity of levetiracetam did not change within a 4-h period under the simulated gastric conditions, and no significant degradation was observed for the different storage temperatures tested. Discussion & conclusion: An accurate and sensitive quantitative method was developed for the determination of levetiracetam in drug samples. The stability of the drug active compound was monitored under various storage and gastric conditions. The levetiracetam content determined in the drug samples were within ±10% of the value stated on the drug labels.