Glassy Carbon Electrode Modified with CB/TiO2 Layer for Sensitive Determination of Sumatriptan by Means of Voltammetry and Flow Injection Analysis

Abstract

Sumatriptan is an organic chemical compound from the tryptamine group. It is used as a medicine for migraine attacks and in the treatment of cluster headaches. In this work, a new voltammetric method is proposed for highly sensitive SUM determination, using glassy carbon electrodes modified with carbon black and titanium dioxide suspension. The novelty of the presented work is the usage of the mixture of carbon black and TiO2 as glassy carbon electrode modifier for the first time for SUM determination. The mentioned sensor was characterized by great repeatability and sensitivity of measurements, which resulted in the obtention of a wide range of linearity and a low detection limit. The electrochemical properties of the CB-TiO2/GC sensor was characterized using the LSV and EIS method. The effect of different factors on the SUM peak, such as supporting electrolyte type, preconcentration time and potential, or influence of interferents, were tested using the square wave voltammetry technique. The linear voltammetric response for the analyte was obtained in the concentration range of 5 nmol L−1 to 150 μmol L−1 with a detection limit of 2.9 nmol L−1 for a preconcentration time of 150 s in the 0.1 mol L−1 phosphate buffer pH 6.0. The proposed method was successfully applied for highly sensitive sumatriptan determination in complex matrices, such as tablets, urine, and plasma, with a good recovery parameter (94–105%). The presented CB-TiO2/GC electrode is characterized by great stability, it was used for 6 weeks without significant changes in the SUM peak current. Amperometric and voltammetric measurements of SUM under the flow injection conditions were also performed to indicate the possibility of its fast and accurate determination with a time of single analysis of approx. 30 s.

A Novel Composite Voltammetric Sensor Based on Yttria-Stabilized Zirconia Doped with Neodymium-Carbon Black-Nafion Glassy Carbon Electrode for Metoprolol Determination

“…A freeze-dried urine reagent for commercial use was purchased from Medidrug (Barcelona, Spain) and prepared according to the instructions obtained by the manufacturer. The vial's content was diluted with double-distilled water and passed through an RC syringe filter (pore diameter 0.45µm) and then used for metoprolol determination [18,19,48].…”

“…A plasma sample for commercial use was purchased from Biowest and protected from the light and stored in a freezer at −20 • C. For removal of interfering proteins from the samples, the plasma was prepared using the following procedure: 800 µL of plasma was blended with 200 µL of trichloroacetic acid (TCA-10%) and vibrated for 2 min on the vortex. The suspension was separated by means of centrifugation at 10,000 rpm, and was then filtered through syringe filters (pore size 0.45 µm) and used in measurements [18,48,49].…”

“…All electrochemical processes occur on the working electrode. In voltammetry, many types of working electrodes can be applied for the inorganic as well as organic substance determination [18][19][20][21]. A very popular electrode use in voltammetry is the glassy carbon electrode (GCE) with various surface modifiers.…”