Hakan Serbest

In this paper, a green, sensitive, and accurate analytical method was described for the determination of heptachlor at low levels in the GC-MS system. In this context, the preconcentration of heptachlor was achieved by applying the dispersive solid-phase microextraction (DSPME) method prior to the separation and quantification in the GC-MS system. Toner@CuFe₂O₄ nanocomposites were synthesized by the hydrothermal synthesis method and used as the sorbent for the first time in literature. Under the optimal conditions determined by the univariate optimization approach, the limit of detection (LOD) and limit of quantification (LOQ) were found to be 0.61 µg kg⁻¹ and 2,0 µg kg⁻¹, respectively, and the sensitivity of the GC-MS system was enhanced by 68.5-fold. The applicability of the Toner@CuFe₂O₄-DSPME-GC-MS system was assessed by spiking tests applied to soil samples. The recovery results in the range of 93.2% and 105.7% obtained by applying the matrix matching calibration strategy proved the feasibility of the method. The Eco-scale and BAGI tools developed for green and analytical applicability assessment gave scores of 85 and 65, respectively, confirming that the method is environmentally friendly and analytically applicable.

FeSbO ₄ nanoparticles were fabricated under hydrothermal synthesis conditions and utilized for the first time as sorbent materials for the preconcentration/separation of Ni ions.

In this study, a facile, rapid, and cost-effective method was developed for the determination of lead ions using copper-metal organic framework (Cu-MOF) nanoparticles based dispersive solid phase extraction (DSPE) in slotted quartz tube-flame atomic absorption spectrometry (SQT-FAAS) system. Cu-MOF nanoparticles were used as sorbents, and SQT was used to increase the residence time of lead atoms in the light path. The limit of detection (LOD) and limit of quantification (LOQ) of the Cu-MOF-DSPE-SQT-FAAS system were calculated as 7.1 µg L⁻¹ and 23.5 µg L⁻¹ under optimum experimental conditions, respectively. The regression coefficient (R²) was found to be 0.9967, and the linear operating range was determined between 15 and 300 µg L⁻¹. Thanks to the developed method, a 103.7-fold improvement was achieved for the sensitivity of the traditional FAAS system by comparing the slopes of the linear calibration plot equations. The feasibility of the proposed method was investigated by spiking experiments with utilizing the stream water samples. The good recovery results obtained in the range of 90.8% to 127.1% demonstrated the applicability of the developed method to river water samples with high accuracy and precision. Cu-MOF structures have been employed for the first time for the preconcentration of Pb ions, and their prominent surface properties suggest that they may also be applicable for other analytical processes for different analytes.

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.

Manganese ferrite (MnFe₂O₄) nanoparticles-assisted dispersive solid-phase extraction (MF-DSPE) was developed for the determination of rhodium (Rh) in soil samples at low levels with good accuracy and precision by flame atomic absorption spectrometry (FAAS). The synthesis of MnFe₂O₄ nanoparticles was carried out in a microwave system by a rapid procedure. The pH, buffer volume, sorbent mass, sample volume, eluent volume/concentration, and mixing time were identified with univariate optimization. Under the optimal conditions, the limits of detection (LOD) and quantitation (LOQ) were 4.4 and 14.7 µg L⁻¹, respectively. The sensitivity was improved by 121.9-fold based upon comparison of the limits of detection with and without preconcentration. The applicability was investigated by spiking rhodium into soil extracts, and good recovery results between 91.2% and 122.2% were achieved using matrix matching calibration. The results showed that MF-DSPE-FAAS determines low levels of rhodium in soil with good accuracy and precision.