Improving the Analytical Performances of the Ibuprofen Voltammetric Determination at Bare Graphite Electrode Using Semi-Derivative Linear Sweep Voltammetry

Abstract

In this work, a bare graphite electrode was applied for the simple and cost-effective ibuprofen determination. Analytical performances improvement was achieved taking advantage of the semi- derivative processing of the signal obtained by linear sweep voltammetry. The semi-differentiation led to transformation of the asymmetric and broad ibuprofen current peaks into much more symmetrical, bell-shaped and detectable semi-derivative signals, as well as to sensitivity enhancement. Under the optimized conditions (3 min accumulation time and pH 4.5) the peak current varied with ibuprofen concentrations in two linear ranges: from 2 μmol L-1 to 100 μmol L-1 and from 100 μmol L-1 to 500 μmol L-1 with a limit of detection of 0.6 μmol L-1 (S/N=3). The method was successfully applied for the determination of ibuprofen in pharmaceutical formulations with satisfactory recovery values (99.2%– 101.6%). The proposed sensor also demonstrated good selectivity and reproducibility.