Investigating The Rapid Detections Of PDE-5 Inhibitors And Pericarpium Papaveris In Food

The determinations of the phosphodiesterase type 5 enzyme (PDE-5) inhibitors added into health products and pericarpium papaveris in hotpot condiments were investigated thoroughly.A method for detection of PDE-5 inhibitors added illegally into health products was established by thin-layer chromatography and surface enhanced Raman spectroscopy(TLC-SERS) combined with BP neural network. The detecting conditions of six PDE-5 inhibitors, including acetildenafil, sildenafil, hydroxyhomo sildenafil, vardenafil,thioaildenafil and pseudo vardenafil, were optimized. Good separation efficiency was achieved by using silica gel plates GF254 coupled with the optimal eluent(ethanol/n-hexane/ammonium hydroxide: 70:30:1, v/v/v). 4 ?L (1?L × 4) of 10 mM silver colloids were added to the spot of the TLC plate. 50 mW laser power, 10 s exposure times and 10 accumulations were chosen in the detection regime. Under the optimized experimental conditions, the artificially produced model samples were analyzed to evaluate the accuracy of this method. The limit of detection (LOD) less than 5 mg/kg was obtained.Base on the better sensitivity of this method, the real samples have been detected accurately and confirmed by high performance liquid chromatography (HPLC), which shown that the results fall in line.A method for the detection of pericarpium papaveris in hotpot condiments was put forward using the QuEChERS (an acronym for quick, easy, cheap, effective, rugged, and safe) with thin-layer chromatography and surface enhanced Raman spectroscopy(TLC-SERS). In this study, the papaverine and noscapine were detected to indirectly identify the pericarpium papaveris in hotpot condiments, because they were the major components of the pericarpium. The feasibility of the QuEChERS for the detection using TLC-SERS was evaluated. And the derivative spectrum (the first derivative spectra and the second derivative spectra) were used to reduce the fluorescence interference of the analyte itself via support vector machine (based on the particle swarm optimization). The real samples have been detected and the results showed that none of the three samples contained papaverine and noscapine. The three samples were tested using HPLC to further verify the detection results, and both of the HPLC and TLC-SERS results were the same.