title: Simultaneous determination of sildenafil, vardenafil and tadalafil as forbidden components in natural dietary supplements for male sexual potency by high-performance liquid chromatography-electrospray ionization mass spectrometry.
abstract: A high-performance liquid chromatographic method coupled with ultraviolet detection and electrospray ionization mass spectrometry (HPLC-UV-ESI-MS) was developed for simultaneous determination of banned additives-sildenafil, vardenafil and tadalafil in dietary supplements for male sexual potency. The separation was achieved on a C18 column with acetonitrile and aqueous solution (20 mmol ammonium acetate, 0.2% formic acid) as mobile phase at a flow rate of I ml/min with a linear gradient program. UV detection was at 292 nm. Identification of drugs was accomplished using ESI-MS. Good linearity between response (peak area) and concentration was found over a concentration range of 0.8-80 microg/ml for sildenafil; 2.25-225 microg/ml for vardenafil; and 1.1-110 microg/ml for tadalafil, with regression coefficient is better than 0.999. The recovery of the method ranged from 93.3 to 106.1%, and the relative standard deviation varied from 2.0 to 5.6% (n = 6). The method has been successfully applied to the analysis of practical samples of natural dietary supplements.
authors.affiliation: Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Hunan Normal University, Changsha 410081, China.
authors.forename: Xiaolan
authors.initials: X
authors.lastname: Zhu
authors.forename: Song
authors.initials: S
authors.lastname: Xiao
authors.forename: Bo
authors.initials: B
authors.lastname: Chen
authors.forename: Fei
authors.initials: F
authors.lastname: Zhang
authors.forename: Shouzhuo
authors.initials: S
authors.lastname: Yao
authors.forename: Zutian
authors.initials: Z
authors.lastname: Wan
authors.forename: Dajin
authors.initials: D
authors.lastname: Yang
authors.forename: Hongwei
authors.initials: H
authors.lastname: Han
mesh_terms: D002243:Carbolines / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D019587:Dietary Supplements / Q000032:analysis*; D004340:Drug Contamination; D007093:Imidazoles / Q000032:analysis*; D010726:Phosphodiesterase Inhibitors / Q000032:analysis*; D010879:Piperazines / Q000032:analysis*; D011687:Purines; D000068677:Sildenafil Citrate; D021241:Spectrometry, Mass, Electrospray Ionization; D013450:Sulfones / Q000032:analysis*; D000068581:Tadalafil; D014227:Triazines / Q000032:analysis*; D000069058:Vardenafil Dihydrochloride
chemical_list: D002243:Carbolines; D007093:Imidazoles; D010726:Phosphodiesterase Inhibitors; D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014227:Triazines; D000069058:Vardenafil Dihydrochloride; D000068581:Tadalafil; D000068677:Sildenafil Citrate