Electrochemical Quantification of Paracetamol in Locally Available Pain-Killer Drug Formulaions, Using Cobalt Hexacyano Ferrate Based Carbon Paste Sensor, Voltammetrically

R. C. Saini¹*, Letemariam Gebresilassie², Tadele Hunde¹, Mekonen Tirfu¹, Rishi pal^3
1Department of Chemistry, College of Natural and Computational Sciences, Mekelle University, P.O. Box -231, Mekelle, Ethiopia.
²Department of Chemistry, Mizan Tepi University, P.O. Box -Mizan, Ethiopia.
³SBMN Institute of Pharma Sciences and Research, Baba Mastnath University, Asthal Bohr -124021, Haryana, India.

A B S T R A C T
Paracetamol, because of its palliative characteristics has found its worldwide applications in the service of humankind to get divest-off headache, backache, and arthritis including post-operative pains. At present, the electrochemical oxidation studies of Acetaminophen (APAP) at 0.1M phosphate buffer solution of pH-7 using cobalt hexacyano ferrate modified carbon paste electrode at scan rate 50 mV/s employing cyclic voltammetry (CV) and Differential pulse voltammetry (DPV) techniques have been carried out. The different experimental and voltammetric parameters that have their profound effect on the electrochemical response of paracetamol, like buffer pH, scan rate, concentration and mass-ratio of modified sensor have been worked out to set the optimum working conditions for present studies. On using these working parameters, the nature of electrochemical oxidation process involved at the sensor/ analyte interface has been observed an irreversible involving transference of two electrons and two protons, along with the diffusion controlled interfacial operation of the process. The enormity of diffusion coefficient (D), electron transfer coefficient (α) and heterogeneous transfer rate constant (k) have been calculated and cited as 7.3  10^-6 cm²s^-1, 0.541 and 3.2  10^-6 cm s^-1, respectively. The sensor has displayed outstanding electrochemical catalytic activity towards the oxidation of APAP. Under optimized parameters, DPV technique has given away the improved sensitivity for APAP in low analyte concentrations and responded a linear behavior over 1.0 to 10.0 µML^-1 range,  following the regression equation  “Ip (μA) = 1.6126 C (μM) + 34.5 with correlation coefficient, R = 0.999 for repititions, n = 5”. The limit of detection (LOD) calculated from oxidation peak currents in the linear range using, LOD = 3s/m, found 4.6 x 10^-7mol/L.
Keywords: Cobalthexacyanoferate, cyclic voltammetery, differential pulse voltammetry, paracetamol