Development of a molecularly imprinted polymer for selective extraction followed by liquid chromatographic determination of sitagliptin in rat plasma and urine

A novel water-compatible molecularly imprinted solid-phase extraction (MISPE) combined with zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) method for selective extraction and determination of sitagliptin in rat serum and urine was developed and validated. The effects of progenic solvents, pH, cross linker and amount of monomer were studied to optimize the efficiency and selectivity. The adsorption kinetics and isotherms were measured. The molecularly imprinted polymer (MIP) showed good specific adsorption capacity with an optimum of 180 mg/g at pH 7.5 and selective extraction of sitagliptin from rat plasma and urine. The recovery of sitagliptin from rat urine and plasma was >98%. The limits of detection (LOD) and quantification (LOQ) were 0.03 and 0.10 mu g/L respectively. The proposed method overcomes the matrix effects of phospholipids generally encountered while preparation of plasma samples by precipitation of proteins. (C) 2011 Elsevier B.V. All rights reserved.