Amperometric determination of promethazine in tablets using an electrochemically reduced graphene oxide modified electrode

Abstract

Graphene films were prepared on a glassy carbon electrode for amperometric determination of promethazine hydrochloride in pharmaceutical products. This modified sensor was prepared by chemical oxidation of graphite powder followed by product exfoliation in ultrapure water using an ultrasonic bath. Then, the resultant graphene oxide was electrochemically reduced in 0.10 mol L À1 acetic acid-sodium acetate (pH = 5.0) on a glassy carbon electrode surface. The proposed sensor exhibited reproducible amperometric responses in a wide linear range from 1.99 Â 10 À6 to 1.03 Â 10 À3 mol L À1 at +0.78 V (vs. Ag/AgCl).Low detection and quantification limits (1.99 Â 10 À7 mol L À1 and 6.63 Â 10 À7 mol L À1 , respectively) were achieved. This method was applied to the analyses of commercial tablet samples and all results were in good agreement with those obtained using spectrophotometry and high-performance liquid chromatography.

Polyethylenimine-Multi-Walled Carbon Nanotubes/Glassy Carbon Electrode as an Efficient Sensing Platform for Promethazine

“…This result is in agreement with previous studies that reported that the electrochemical oxidation of PMZ is favored in acidic medium. 38,40,48 In addition, Fig. 4a also shows that the peak potential changes linearly toward less positive values with the increase of the pH between 2.0 and 8.0, being described by the following equation: E p /V = 0.73 ± 4.64 × 10 −3 − 0.053 ± 1.62 × 10 −3 pH, r = 0.9859.…”

“…The electrocatalytic effect also can be noted in the current increase 6.5 times in relation of the bare electrode. In addition to the increase in the current observed for the A 9 process, with the inclusion of fMWCNT and the modification of the GCE, it was possible to observe a more positive potential process, process A 10 , related to the formation of the dioxygenated sulfoxide structure, 34,[36][37][38] Scheme 1. For cathodic sweep, a characteristic broad composed by two process could be observed.…”

“…The analytical performance of fMWCNT-PEI/GCE was compared with the published reports for PMZ detection (Table I). Although involving different transducers, and some of them based on different detection techniques (such as amperometry, 38 cyclic voltammetry, 53,54 and differential pulse voltammetry 33,37,39,55,56 ), and electrolytes (such as H 2 SO 4 , 38 phosphate, 37,39,40,[53][54][55]57 and acetate buffer 33 ) at a variety of pH, similar linear ranges were overall obtained for all the studies, including this work, with the exception of Alizadeh et al 53 These authors 53 developed the most sensitive but a much more complex transducer using a carbon paste electrode modified with molecularly imprinted polymer, which presents two 57 and being comparable with those reported for a GCE modified with reduced graphene oxide, 38 bare GCE 56 and a graphite powder-ionic liquid paste coated gold electrode. 54 The noted differences in DL values may be due to the diverse formulas used to calculate the DL, since several studies used the standard deviation of blank signal for DL determination, but also, they may be caused by the different calculated sensitivities.…”

Determination of promethazine in forensic samples using multi-walled carbon nanotube-gold nanoparticle electrochemical sensor

“…The employment of electrodes modied with carbon materials, 13,14 nano-sized metals, 15,16 metal oxides, [17][18][19] semiconductors, 20 and biomaterials [21][22][23] have signicantly improved the sensitivity of the electrochemical detection of PMZ. Carbon nanomaterials and metal nanoparticles, such as carbon nanotubes (CNTs) and gold nanoparticles (AuNPs), have been particularly studied due to their unique properties.…”

“…24,25 AuNPs provide a large surface-to-volume ratio, strong adsorption properties, and high conductivity. 26,27 These materials have been proposed as platforms for PMZ determination in various real sample types, predominantly pharmaceutical formulations, [13][14][15]28 as well as environmental water samples and biological uids. 19,20,29 In our work, we specically focus on analyzing the forensic evidence related to PMZ abuse, which includes samples of recreational drug beverages, suspected counterfeit pharmaceuticals, and saliva samples from overdosed users.…”