Abstract:A high performance liquid chromatography-photodiode array detection (HPLC-PDA) method was established for detecting 14 chemical drugs illegally added to health products and Chinese patent medicines for sexual enhancement. The detected compounds comprised 11 phosphodiesterase inhibitors that met the supplementary test criteria, as well as three typical serotonin reuptake inhibitors. The samples were extracted with acetonitrile and then separated using an Agilent 5 HC-C18 (2) chromatographic column (250 mm×4.6 mm, 5 μm) through gradient elution with a mobile phase consisting of acetonitrile, methanol, ammonium, and acetate. The mobile phase pH was 5.0 and 7.0, flow velocity was 1.0 mL/min, column temperature was 30 ℃, sample size was 10 μL, PDA detector scanning range was 190~400 nm, monitoring was conducted at 254 and 238 nm, and the compounds were quantified using an external standard. The separation of 14 chemical drugs was adequate, the linear relationship was good within a certain concentration range, and the correlation coefficient r was >0.999 9. The average recoveries (n = 9) of low, medium, and high concentrations were 99.9%~101.0% with RSD <2%, and the detection limit was 0.016~0.201 μg/mL. A total of seven positive samples were detected in 91 batches of marketed products; the addition of three compounds was illegal. The method is simple, accurate, specific, and sensitive; therefore, it is suitable for daily supervision and inspection.
