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This paper describes non-enzymatic phenol determination using poly(3-methylthiophene) coated Pt electrode. Modified electrode was prepared on Pt disc surface in dichloromethane medium containing 500 mM 3-methylthiophene (3MT) and 100 mM tetrabuthylammonium perchlorate (TBAP). This electrode was used for amperometric determination of phenol in NaHSO4 / Na2SO4 (SBS) solution at pH 2.0. For this purpose, 0.70, 0.80 and 0.90 V potentials were applied and results were compared. Limit of detection and linear range were found as 4.22x10-5 and 1.41x10-4 – 4.00 mM (with R2=0.9932) at 0.90 V working potential, respectively. Repeatability of method was tested by using at least three modified electrode for 0.5, 1.0 and 2.0 mM phenol concentrations and relative standard deviation (RSD were found as 2.49%, 1.92% and 2.75%, respectively. To test the accuracy of method and matrix effect, phenol determination was carried out for 1.0 and 2.0 mM phenol concentrations in artificially contaminated river water samples at optimum condition and recovery values were found as 96.44% and 99.60%, respectively. Proposed method was found as simple, rapid and economic for phenol determination. Keywords: Phenol; Poly(3-methylthiophene); Amperometric determination; Non-enzymatic DOI: 10.17350/HJSE19030000030 Full Text

A Pt electrode modified by polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine) was used for amperometric determination of epinephrine in a solution of NaHSO4/Na2SO4 (pH 2.0). For these studies, potentials between 0.40 and 0.50 V were applied, and the best response was obtained at 0.45 V. The limit of detection, limit of quantification, and the linear dynamic range were 1.23 × 10−4, 4.10 × 10−4, and 4.10 × 10−4 to 100.0 mmol L−1, respectively. These results were compared with determinations using Pt electrodes that were coated and uncoated with homopolymers. To check the accuracy of the developed method and the matrices interference, determination of epinephrine was performed in human serum samples using this modified electrode. The epinephrine concentrations were adjusted to 1.0 and 5.0 mmol L−1, and recovery values were calculated as 100.4% and 96.8%, respectively. It is significant that the determination of epinephrine was carried out at a lower potential (0.45 V) than the oxidation potential of epinephrine (0.65 V) without any matrix effect.

A polyaniline–poly(3-methylthiophene)–poly(3,3′-diaminobenzidine) film was deposited on a platinum disc electrode in dichloromethane containing tetrabuthylammonium perchlorate supporting electrolyte and used for the amperometric determination of dopamine. At a pH of 2.0, this electrode allowed successful determination at a lower potential than the oxidation potential of dopamine. The limit of detection, limit of quantification, and the linear dynamic range were determined to be 1.63 × 10−5 mM, 5.43 × 10−5 mM and 5.43 × 10−5 to 100.0 mM (R2 = 0.997), respectively. The reproducibility was investigated by using three different films and good analytical results were obtained. In addition, the modified electrode was successfully employed to determine dopamine in human serum with good recoveries.

WOS: 000374187700008 PubMed: 26970788 Modified electrode based on combination of different conductive polymers (polyaniline -poly(3-methylthiophene) poly( 3,3'-diaminobenzidine) (PANI - P3MT - PDAB)) was previously synthesized in dichloromethane containing HClO4 and tetrabutylammoniumperchlorate (TBAP) as supporting electrolyte. Herein, the determination of hydroquinone (HQ) with amperometric I-t method over this modified and its homopolymers coated electrode was successfully carried out in river water as a real sample and in solution consisting of NaHSO4/Na2SO4 (pH 2.0). For this method, potentials between 0.45 V and 0.65 V were applied and the best analytical response was obtained at 0.55 V using this modified electrode when compared to its homopolymers. the limit of detection (LOD), limit of quantification (LOQ), the linear dynamic range and regression coefficient (R-2) were found as 1.31 x 10(-4) mM, 4.37 x 10(-4) mM, 4.37 x 10(-4)-95.0 mM and 0.998, respectively. These results were compared to homopolymers coated and uncoated Pt electrodes. For checking on the accuracy of the developed method and the matrices interference, determination of HQ was performed in artificially contaminated river water samples with HQ concentration of 5.0 mM and 10.0 mM using this modified electrode and recovery values were calculated as 100.6% and 100.1%, respectively. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111T445]; Recep Tayyip Erdogan University, Unit of Scientific ResearchRecep Tayyip Erdogan University [2013.102.02.3] This research was supported by the Scientific and Technological Research Council of Turkey (TUBITAK) (Project no: 111T445) and Recep Tayyip Erdogan University, Unit of Scientific Research (Project no: 2013.102.02.3). We thank to Dr. Selcuk Demir (Recep Tayyip Erdogan University, Faculty of Science & Arts, Department of Chemistry, Rize) for improving the language of this munucript.

WOS: 000361556500025 Poly(vinylferrocenium) perchlorate-poly(3,3'-diaminobenzidine) (PVF+ClO4--PDAB) composite film was synthesized electrochemically for the first time on Pt disc electrode in a dichloromethane solution containing poly(vinylferrocene) (PVF) polymer, 3,3'-diaminobenzidine (DAB) monomer and tetrabutylammonium perchlorate as supporting electrolyte. This modified electrode was characterized using cyclic voltammetry, Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometry, atomic absorption spectroscopy (AAS), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) methods and it was used for amperometric determination of hydroquinone (HQ) at potential ranges of 0.40 and 0.60 V. the best analytical results for HQ was obtained at 0.45 V in NaHSO4/Na2SO4 solution (pH 2.0) and limit of detection, limit of quantification and linear response range were found as 7.469 x 10(-5), 2.489 x 10(-4) and 2.489 x 10(-4)-65.0 mmol L-1 (R-2 = 0.996), respectively. These results were compared to poly(3,3'-diaminobenzidine) (PDAB) coated and uncoated Pt electrodes. the best analytical results were obtained with composite film because of behavior as electron transfer mediator of PVF. Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [111T445]; Recep Tayyip Erdogan University Scientific Research Projects UnitRecep Tayyip Erdogan University [2013.102.02.3] Support to this work by the Scientific and Technological Research Council of Turkey (TUBITAK) (Project No. 111T445) and Recep Tayyip Erdogan University Scientific Research Projects Unit (Project No. 2013.102.02.3) is greatly appreciated. We thank Associate Professor Dr Selcuk Demir (Recep Tayyip Erdogan University, Faculty of Sciences & Arts, Department of Chemistry, Rize, Turkey) for improving the language of this manuscript.

Poly(3-methylthiophene) (P3MT) film was synthesized by potentiodynamic method on Pt electrode in methylene chloride solution containing 0.10M tetrabuthlammonium perchlorate supporting electrolyte and used for the determination of hydroquinone (HQ) with amperometric I–t method in solution consisting of NaHSO4/Na2SO4 (SBS; pH 2.0). This modified electrode has a lower working potential and good operational stability due to reducing electrode fouling when compared with the direct oxidation of HQ at the bare Pt electrode. Limit of detection, limit of quantification, and the linear response range were found to be 1.32 × 10−5 mM, 4.41 × 10−5 mM, and between 4.41 × 10−5 – 50.0 mM (R2 = 0.997), at 0.50 V versus saturated calomel electrode, respectively. HQ determination in complex matrix was checked using real samples to demonstrate the applicability of modified electrode. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40859.