Sensitive Analysis of Epilepsy Drug, Phenobarbital, Based on Column Type Solid Phase Extraction and HPLC-DAD System

An analytical approach has been developed for the sensitive determination of Phenobarbital, which is used as an antiepileptic drug molecule. The analysis of this active molecule, which has a very limited study even for its direct determination in the literature review, is mostly done with highly complex device systems such as LC-MS. In analysis with conventional HPLC systems, the limit of detection cannot be in most cases lower than 1 µg mL-1 With this study, a separation and preconcentration method based on solid phase extraction (SPE) was developed for trace phenobarbital molecules, so that even very low concentrations could be monitored. In the proposed method, the target molecules were enriched with column type SPE method, and then their analysis were carried out by with the HPLC-DAD system. As an SPE sorbent, a polymeric material, poly(ethylene glycol dimethacrylate-N-methacryloyl-L-tryptophan methyl ester) [poly(EGDMA-MATrp)], was used in extraction experiments. Experimental variables such as pH of medium, type and amount of desorption solvent, electrolyte effect have been studied and optimized step by step. The linear working range under the optimized conditions were determined in the range of 10.00-400.00 ng mL-1 with the limit of detection as 3.57 ng mL-1. Quantitative results were obtained in recovery experiments with the help of model solutions including phenobarbital molecule