"One-shot" analysis of PDE-5 inhibitors and analogues in counterfeit herbal natural products using an LC-DAD-QTOF system.

摘要: A highly selective and robust method for simultaneous screening confirmation of target non-target phosphodiesterase type 5 (PDE-5) inhibitor analogues within a single chromatographic run in counterfeit herbal products was developed. The protocol, based on an easy rapid extraction with water/acetonitrile 1 % formic acid solution, followed by sonication centrifugation, exploits LC-diode array detector-quadrupole-time-of-flight (DAD-QTOF) system. optimized both at high concentrations trace levels. These two situations are typically encountered pharmaceutical formulations food supplements. Carryover effects, never reported before occurring mainly vardenafil, were overcome using polymer-based column. An in-house validation carried out five blanks different bulk matrices spiked seven standard analytes, namely yohimbine, sildenafil, tadalafil, homosildenafil, pseudovardenafil hydroxyhomovardenafil. Reliable quantitation possible conventional solution all the samples considered, as matrix effects eliminated. Accuracy ranged from 80.9 to 108.1 overall relative deviation (RSD) <11 (N = 15), measured 1.0, 5.0 10.0 μg/g. Limits detection (LODs) obtained ensured determination cross contaminations nanogram per gram database 82 PDE-5 implemented automatic analysis. Among 26 dietary supplements remedies marketed erectile dysfunctions, three found be contaminated registered unregistered synthetic inhibitors, i.e. dimethylsildenafil thiodimethylsildenafil or thiomethisosildenafil. occurrence such contaminations, levels dosage, indicates illicit use analogues.