Dumbbell-shaped Stir Bar Coated With The Dendrimer-based Mips For Selective Extraction And Analysis Of Vardenafil And Its Analogue Sildenafil In Health Foods

A novel dendrimer-based molecularly imprinted polymers(MIPs)coated dumbbell-shaped stir bar(DSB)was developed to enrich and analyse two kinds of phosphodiesterase type 5(PDE-5)inhibitors in health foods(HFs).The MIPs,with vardenafil as template molecule and methacrylic acid(MAA)as functional monomer,were synthesized on the surface of the dendritic-grafting DSB which was filled with magnetic core as substrate.The MIPs-DSB possessed mechanical stability,high adsorption capacity and good selectivity for vardenafil and its analogue sildenafil.A method for the determination of vardenafil and sildenafil in HFs was established by SBSE coupled with HPLC-UV.The contents of vardenafil and sildenafil were found to be 3.65 and 2.66 ?g g-1,respectively,and the average recoveries in spiked HFs were 86.5-91.8%with a relative standard deviation(RSD)below 5%.All results revealed that the MIPs-DSB coupled with HPLC-UV could be applied to the highly selective extraction and sensitive determination of trace analytes in complex matrix.