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 x 10(-7) mol L-1) was reached. In addition, relative standard deviation of repeated measurements (c(5-ASA) = 5 x 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.