title: Synthesis of core-shell magnetic molecularly imprinted polymers and detection of sildenafil and vardenafil in herbal dietary supplements.
abstract: An analytical procedure for selective extraction of sildenafil and vardenafil in herbal dietary supplements (HDSs) has been set up by using the magnetic molecularly imprinted polymers (MMIPs) as the extraction and clean-up materials, followed by high performance liquid chromatography-ultraviolet (HPLC-UV). The MMIPs were prepared by a surface molecular imprinting technique, using Fe(3)O(4) magnetite as a magnetically susceptible component, sildenafil as template molecule, 2-(trifluoromethyl) acrylic acid (TFMAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as polymeric matrix components. The MMIPs were characterized by transmission electron microscope (TEM), Fourier transform infrared spectrometer (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM), respectively. The heterogeneity of the MMIPs was modeled with the Freundlich isotherm equation. The resulting MMIPs had high recognition ability and fast binding kinetics for sildenafil. The MMIPs were used as dispersive solid-phase extraction (DSPE) materials to selectively extract sildenafil and vardenafil from HDSs, the contents of sildenafil and vardenafil were found to be 8.05 and 3.86 μg g(-1), respectively, and the average recoveries in spiked HDSs were 70.91-91.75% with a relative standard deviation (R.S.D.) below 7%. The MMIPs were successfully used to selectively enrich and determine sildenafil and vardenafil from HDSs.
authors.affiliation: School of Pharmacy, Nanjing Medical University, Nanjing, PR China. dmj0817@yahoo.cn
authors.forename: Meijuan
authors.initials: M
authors.lastname: Ding
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Wu
authors.forename: Lihua
authors.initials: L
authors.lastname: Yuan
authors.forename: Shu
authors.initials: S
authors.lastname: Wang
authors.forename: Yun
authors.initials: Y
authors.lastname: Li
authors.forename: Ruoyu
authors.initials: R
authors.lastname: Wang
authors.forename: Tingting
authors.initials: T
authors.lastname: Wen
authors.forename: Shuhu
authors.initials: S
authors.lastname: Du
authors.forename: Xuemin
authors.initials: X
authors.lastname: Zhou
mesh_terms: D000327:Adsorption; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements; D029001:Herbal Medicine; D007093:Imidazoles / Q000032:analysis*; D007700:Kinetics; D008280:Magnetics; D010726:Phosphodiesterase Inhibitors / Q000032:analysis*; D010879:Piperazines / Q000032:analysis*; D011108:Polymers / Q000737:chemistry*; D011687:Purines / Q000032:analysis; D000068677:Sildenafil Citrate; D013056:Spectrophotometry, Ultraviolet; D013450:Sulfones / Q000032:analysis*; D014227:Triazines / Q000032:analysis; D000069058:Vardenafil Dihydrochloride; D014961:X-Ray Diffraction
chemical_list: D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011108:Polymers; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068677:Sildenafil Citrate