Browsing by Author "Kemer, Baris"

Now showing 1 - 4 of 4

Citation Count: 3
Fe³⁺ - Ion Selective Electrode Developed as a Detector in Flow Injection Analysis
(Bentham Science Publ Ltd, 2015) Demir, Ersin; Kemer, Baris; Isildak, Ibrahim; Aboul-Enein, Hassan Y.
A new polyvinyl chloride (PVC) membrane Fe3+ - ion selective electrode was constructed as a detector for the analysis Fe3+ using a home-made low-volume flow through cell. Optimum working conditions for the flow injection analysis (FIA) measurements were examined. In addition, under optimum conditions, potentiometric performance characteristics of the Fe3+ ion-selective electrode were investigated. Electrode had a linear response in the concentration range of 1.0 x 10(-3)-1.0 x 10(-6) M (R-2=0.9961, y=24.7+772.0). Reproducibility of the electrode responses was very satisfied. The potential of Fe3+ ion selective electrode was decreased intra and inter day 0.9 % and 3.7% respectively. The designed flow-through cell system as Fe3+ detector revealed sampling rates of approximately 50 injections per hour. The obtained results in FIA were in a good agreement with AAs results at % 95 confidence level for each syrups.
Citation Count: 15
A Novel all Solid-State Contact PVC-Membrane Beryllium-Selective Electrode Based on 4-Hydroxybenzo-15-Crown-5 Ether Ionophore
(Bentham Science Publ Ltd, 2018) Isildak, Ibrahim; Attar, Azade; Demir, Ersin; Kemer, Baris; Aboul-Enein, Hassan Y.
Aim: A novel all solid-state contact PVC-membrane beryllium-selective electrode based on 4-hydroxybenzo-15-crown-5 ether as an ionophore is described. Results: The best performance was obtained with a membrane composition of 4% ionophore, 67% dioctyl sebacate (DOS), 28% poly(vinyl chloride) (PVC), and 1% potassium tetrakis (p-chloro) phenylborate (KTClPB) (w/w). The all solid-state contact PVCmembrane beryllium-selective electrode together with an Ag/AgCl reference electrode exhibited sub-Nernstian response with a slope of 22 +/- 1 mV/decade to beryllium ions from 1.0x10(-6) to 1.0x10(-1) M, and resulted a considerably low detection limit of 6.2x10(-7). The electrode had a good performance in selectivity over a wide range of interfering cations tested. It showed a working pH range between 4.0-8.2 with fast response time (< 10 s) and a good reproducibility. Conclusion: The all solid-state contact PVC-membrane beryllium-selective electrode developed was successfully applied in potentiometric titration of Be2+ ions with EDTA.
Citation Count: 11
A Novel Iron(III)-Selective Membrane Potentiometric Sensor Based on 5-Chloro-3-[4-(trifluoromethoxy) phenylimino] Indolin-2-one
(Bentham Science Publ Ltd, 2015) Demir, Ersin; Kemer, Baris; Bekircan, Olcay; Aboul-Enein, Hassan Y.
A novel polyvinyl chloride (PVC) membrane sensor that is highly selective to Fe3+ ions was prepared by using 5-chloro-3-[4-(trifluoromethoxy) phenylimino] indolin-2-one (CFMEPI) ionophore. The sensor exhibits a Nernstian response for Fe3+ ions over a wide concentration range (1.0 x10(-2) -1.0x10(-6)M) with a slope of 46.7 +/- 0.5 mV per decade. The sensor has a response time of 20s and can be used for at least 3 months without any measurable divergence in potential. It was concluded that the sensor response was pH independent in the range of 4.0-8.61. The sensor has some advantages such as short analysis time, particularly high selectivity towards iron (III). The sensor was used successfully for direct determination of Fe3+ in several synthetic and real samples with satisfactory results.
Citation Count: 3
A novel potentiometric pH electrode based on sulfated natural Fe₃O₄ and analytical application in food samples
(Springer, 2018) Kemer, Baris; Demir, Ersin
A novel solid state potentiometric pH electrode based on sulfated natural Fe3O4 silicone was fabricated. The optimum potentiometric performances such as Nernstian response, response time, selectivity, life-time and reproducibility of pH electrodes were investigated by using a computer-controlled potentiometric device. Moreover, the potentiometric performance of the solid state pH electrodes was studied with different mixtures sulfated natural Fe3O4, silicone and graphite powder. The best potentiometric behavior of proposed pH electrode was obtained with a composition of 20% (w/w) sulfated natural Fe3O4, 40% (w/w) graphite powder and 40% (w/w) silicone. The sub-Nernstian response for pH electrode was exhibited with a slope of 30.8 +/- 1.4mV/pH (r=0.9963) from pH 2 to pH 12. In addition, the dynamic response time was found as 10s in acidic medium and further the proposed pH electrode can be used for at least 1year without any significant slope of the pH-potential curve. The selectivity coefficient of pH electrode was interpreted according to fixed interference method in the presences of Na+, Li+, K+, NH4+, SO42, CH3COO and NO3 ions. The reproducibility of pH electrode was calculated in pH 4 and pH 6 phosphate buffers and it was found as 0.24 RSD (%) and 0.27 RSD (%) respectively. The proposed pH electrode was used to determine of pH in acidbases titration compared with glass pH electrode and is highly stable in corrosive systems including HF solution. Terminally, the pH value was successfully determined in some soft drinks and milk samples by proposed solid state pH electrode at 95% confidence level with satisfactory agreement compared with glass pH electrode.