Simultaneous electrochemical determination of 4-aminophenazone and caffeine at electrochemically pre-treated graphite pencil electrode

Abstract

A new and sensitive electroanalytical method for simultaneous determination of selected drugs, 4-aminophenazone (4-AP) and caffeine (CAF) has been developed and validated. Cyclic voltammetry (CV) was used to study the electrochemical behavior of the drugs, while differential pulse voltammetry (DPV) was used to determine 4-AP and CAF simultaneously. A pre-treated graphite pencil electrode (PTGPE) was used as the working electrode, a Ag/AgCl (3.0 M KCl) electrode served as the reference electrode, and a platinum wire as the auxiliary electrode. Determination of drugs was performed in phosphate buffer solution (PBS) of pH ¼ 3.0. The separation of the oxidation peak potentials for 4-AP-CAF was found to be 0.930 V. This difference was large enough to determine 4-AP and CAF individually and simultaneously. The dependence of the current on pH, concentration and scan rate was investigated to optimize the experimental conditions for simultaneous determination. The calibration plots for both the drugs were linear in certain concentration ranges. The linearity range for 4-AP was 1 mM to 11 mM and for CAF 1 mM to 9 mM, the concentration of each drug was varied by keeping the other constant, and achieved lower detection limit of 7.96 Â 10 À8 M for 4-AP and 9.81 Â 10 À9 M for CAF. The developed method was found to be precise, selective and rapid for the simultaneous determination of 4-AP and CAF. The proposed method has been applied for the determination of 4-AP and CAF in real samples.Scheme 1 Chemical structure of 4-AP and CAF.

Zinc Oxide Nanoparticle‐modified Glassy Carbon Electrode as a Highly Sensitive Electrochemical Sensor for the Detection of Caffeine

“…For an irreversible electrode process, E p is defined by the Laviron's equation where E 0 is formal potential and k 0 is the standard heterogeneous reaction rate constant; n is the number of electrons transferred; α refers to charge transfer coefficient; and ν , R , T , and F have their usual meaning. The value of αn can be calculated from the slope of the E p vs. log υ plot.…”

“…Taking T = 298 K, R = 8.314 J/K/mol, and F = 96 480 C/mol, αn was calculated to be 2.11. Generally, α is assumed to be 0.5 in a totally irreversible electrode process . Therefore, the number of electrons ( n ) transferred during electro‐oxidation of CAF was calculated to be ≈4.…”

Electrochemical Sensor for Caffeine Based on a Glassy Carbon Electrode Modified with an Attapulgite/Nafion Film

“…The resort to stripping analyses involving modified electrodes allowed several authors to achieved low detection limits in the quantification of caffeine. Thus, different sensors, including imprinted sol‐gel sensors , chemically modified graphene surfaces , molecularly imprinted polymer devices , gold nanoparticle‐chitosan‐ionic liquid/graphene modified electrode and graphite pencil electrodes electrochemically pre‐treated have been developed for selective determination of caffeine. More recently, Trani et al.…”

Simultaneous electrochemical determination of acetaminophen and metoclopramide at electrochemically pre-treated disposable graphite pencil electrode

“…The pre-treated graphite pencil electrode (PTGPE) has been used as a biosensor in modern electroanalytical field due to its high mechanical rigidity, highly economical, good electrochemical reactivity, ease of modification, renewal of electrode and low background current [1,2]. PTGPE has good application in analysis of drugs, detection of traces of metal ions and 266 neurotransmitters.…”