Yazar "Erulas, Ahmet Fatih" seçeneğine göre listele

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    A new microextraction method for trace nickel determination in green tea samples: Solventless dispersion based dispersive liquid-liquid microextraction combined with slotted quartz tube-flame atomic absorption spectrophotometry
    (Academic Press Inc Elsevier Science, 2020) Erulas, Ahmet Fatih; Saylan, Meltem; Topal, Serkan; Zaman, Buse Tugba; Bakirdere, Emine Gulhan; Bakirdere, Sezgin
    In this study, a simple and novel analytical approach was developed in order to determine nickel at trace levels. For this purpose, a dispersive liquid-liquid microextraction (DLLME) method based on solventless dispersion of extraction solvent was developed to separate/preconcentrate nickel from aqueous solution. Combination of the DLLME method with slotted quartz tube-flame atomic absorption spectrophotometry (SQT-FAAS) lowered the analyte's detection limit. In the DLLME method, the extraction solvent was dispersed into aqueous solution by generating fine droplets through air assisted spraying in order to reduce organic solvent consumption and avoid relative error by reducing multiple operation steps. Complexation of nickel(II) was done by using a Schiff Base synthesized from the reaction between 3,5- dibromosalicylaldehyde and 2-aminophenol. All experimental parameters were optimized comprehensively by the step-by-step approach in order to determine optimum conditions to get maximum absorbance values. Under the optimum conditions, analytical performance values were examined, and limit of detection values were obtained as 286 ng mL-1 for FAAS, 137 ng mL-1 for SQT-FAAS, 7.9 ng mL-1 for DLLME-FAAS and 3.9 ng mL-1 for DLLME-SQT-FAAS. The enhancement in detection power was obtained as 82-folds over the detection limit of the conventional FAAS system. Chinese green tea sample was used in recovery studies to check applicability and accuracy of the developed method. Recovery results were close to 100 % with low standard deviation values (n = 4) and this showed that the method appropriate for the selected matrix.
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    A sensitive and accurate analytical method for the determination of cadmium in food samples: Molybdenum coated T-shape slotted quartz tube flame atomic absorption spectrophotometry
    (Elsevier Sci Ltd, 2020) Kasa, Nursu Aylin; Buyukpinar, Cagdas; Erulas, Ahmet Fatih; Bakirdere, Sezgin
    In this study, a molybdenum coated T-shaped slotted quartz tube atom trap flame atomic absorption spectrophotometry method (Mo coated-T-SQT-AT-FAAS) was developed for the determination of cadmium with on-line preconcentration. Inner surface of T-SQT was coated with molybdenum to enhance the trapping efficiency. Hydrogen gas was used instead of organic solvents to release trapped atoms. Limit of detection and quantification were found to be 0.057 and 0.082 mu g/L, respectively. The developed method has a linear working range between 0.10 and 1.0 mu g/L with a low %RSD value (< 3.7). About 1202 times enhancement in detection power was recorded over the conventional FAAS system. Recovery experiments were used to determine the applicability of the method developed to real samples (linden, milk powder and mint) and significant results (94.4-100.7%) were obtained for the samples spiked at 0.30, 0.50 and 1.0 mu g/L. The method was also applied to Tomato Leaves 1573a SRM to check the accuracy.
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    Combination of stearic acid coated magnetic nanoparticle based sonication assisted dispersive solid phase extraction and slotted quartz tube-flame atomic absorption spectrophotometry for the accurate and sensitive determination of lead in red pepper samples and assessment of green profile
    (Elsevier Sci Ltd, 2020) Zaman, Buse Tugba; Erulas, Ahmet Fatih; Chormey, Dotse Selali; Bakirdere, Sezgin
    This study describes the determination of lead at trace levels by slotted quartz tube flame atomic absorption spectrophotometry (SQT-FAAS) after preconcentration by the help of stearic acid coated magnetic nanoparticle (SAC-MNPs) based sonication assisted dispersive solid phase extraction (SA-DSPE). SAC-MNPs were used due to their easy separation advantages by the application of external magnetic field. All extraction parameters were optimized by response surface methodology based experimental design. The experimented data was evaluated by the analysis of variance. Under the optimum conditions, about 31 folds enhancement in detection power was obtained over the conventional FAAS. The recovery results obtained for samples spiked at 60 and 120 ng mL(-1) were 106.6 and 102.6%, respectively, validating the method as accurate and applicable to the red pepper matrix. The percent relative standard deviations of the results were under 5.0% even at low concentrations that established high precision for replicate extractions and instrumental readings.