Electrochemical determination of ibuprofen by batch-injection analysis using a BORON-doped ultrananocrystalline diamond electrode

In this paper, the evaluation of a boron-doped ultrananocrystalline diamond (BD-UNCD) electrode for the determination of ibuprofen (IBU) in pharmaceutical formulations using batch-injection analysis with amperometric detection (BIA-AD) is presented. The BD-UNCD electrode was characterized by Raman spectroscopy and the electrochemical measurements were carried out before and after anodic pretreatment. An improved electrochemical response for IBU oxidation was observed using BD-UNCD as compared to commercial boron-doped diamond electrode. The optimized method based on the BIA-AD system was carried out by using 2.0 V as the detection potential, a dispensing rate of 211.9 mu L s-1, and an injection volume of 40 mu L in an electrochemical cell containing 30.0 mL of 1.0 mol L-1 HClO4 as the supporting electrolyte. The proposed method provided an analytical curve within a linear dynamic range from 1.84 to 20.0 mu mol L-1 (R2=0.9967) and a limit of detection of 0.55 mu mol L-1. The intra-day (n=10) and inter-day (n=2) precisions for IBU concentrations of 5.0 and 10.0 mu mol L-1 assessed as relative standard deviation (%RSD) ranged from 2.65 to 5.84 %. The accuracy of the method was assessed through the determination of IBU in pharmaceutical samples (tablets and solutions), yielding results that were consistent with those obtained through the comparative method (HPLC-DAD).