Preparation of Monolithic Stationary Phase in Capillary and Conventional Columns, their Characterization and Application

Abstract

This study has been focused on the development of an analytical method for the determination of Paracetamol (PAR) and Chlorzoxazone (CZN) in their combined pharmaceutical formulation using two stationary phases (home-made columns) which were prepared by two developed methods, one of which was in capillary column while the other was in conventional column.

The first preparation method was achieved using a home-made capillary column (0.10mm i.d. × 200mm length), filled with porous cross-linked hexyl polymethacrylate as monolithic stationary phase. The column morphology was characterized by scanning electron microscopy (SEM). The column showed perfect mechanical stability and permeability over the investigated flow range with regression factor R2 0.9994. The capillary column was used to separate PAR and CZN in their pharmaceutical formulation. The method proved to be simple, fast, sensitive, efficient, cost-effective and green approach owing is the combination of the amazing properties of a monolithic material and a miniaturized liquid chromatography, which reduces the analytical costs and the effect on the environmental impact of chromatographic applications. Both components were detected using a 3-nL nano-UV cell fixed at 270nm wavelength. The optimized mobile phase was composed of 1% aqueous formic acid solution and acetonitrile at 40:60 ratio, 1.0μL/min flow rate, 4.0nL injection volume and 50°C column temperature. Under the optimized conditions, PAR and CZN were separated in about 6.5min with chromatographic resolution of 2.37. Using the prepared column, the developed method was fully validated and compared with other reported works.