Voltammetric determination of mesalazine in pharmaceutical preparations and biological samples using boron-doped diamond electrode

Voltammetric method for the determination of non-steroidal anti-inflammatory drug mesalazine (5-ASA) is presented for the first time using boron-doped diamond electrode (BDDE). 5-ASA provides one well-developed SWV oxidation peak at about −900 mV (vs. saturated silver/silver chloride reference electrode) on BDDE. Britton-Robinson buffer (pH 7.0) was chosen as an optimal supporting electrolyte for the determination of 5-ASA using square wave voltammetry (SWV). Parameters of SWV were developed and low limit of detection (7.0 × 10−7 mol L−1) was reached. In addition, relative standard deviation of repeated measurements (c5-ASA = 5 × 10−5 mol L−1, RSDM = 2.7%) and relative standard deviation of repeated determinations (RSDD < 1.5%) were calculated and confirm obtained good results. Applicability of the proposed method was verified by an analysis of a pharmaceutical preparation and spiked human urine.