Analysis of ketoprofen and mefenamic acid by high-performance liquid chromatography with molecularly imprinted polymer as the stationary phase

A simple and sensitive high-performance liquid chromatographic method for simultaneous determination of ketoprofen and mefenamic acid in tablets has been developed. HPLC with UV detection (220 nm) was performed on an analytical column packed with molecularly imprinted polymer (MIP) as the stationary phase. The MIPs are prepared by bulk polymerisation followed by crushing and sieving to the desired particle size. In this paper, we selected ketoprofen, methacrylic acid, and ethylene glycoldimethacrylate as template, functional monomer, and crosslinker in the presence of chloroform as the solvent. The retention times of mefenamic acid and ketoprofen were approximately 5 and 20 min, respectively. In order to compare the chromatographic data from the stationary phase, separation factors (alpha) were given. The values of alpha were 4.36 approximately 4.39 and showed that the MIPs were able to recognize structurally subtle differences from the template molecule. The limits of detection for ketoprofen and mefenamic acid were found to be 0.029 and 0.038 (g/L), while the limits of quantitation were 0.097 and 0.127 (g/L), respectively. Our results showed good accuracy, indicating that a ketoprofen-selective polymer was suitable for ketoprofen and mefenamic acid separations. Therefore, the MIPs are certainly applied to commercial tablet analysis.