Determination of Phosphodiesterase Type 5 Enzyme (PDE-5) Inhibitors and Analogues as Adulterants in Selected Herbal Products using Gas Chromatography–Electron Impact-Mass Spectrometer (GC-EI-MS). Baghdad Sci.J [Internet]. 2020 Dec. 1 [cited 2025 Jan. 27];17(4):1190. Available from: https://bsj.uobaghdad.edu.iq/index.php/BSJ/article/view/4270