Purba , I. S. P.; Supiyani, S.; Nasution, H. munandar; Lubis , M. S. Analysis of Nicotine Content and Identification of Bioactive Compounds in Gayo-Origin Tobacco Leaf (Nicotiana Tabacum L.) Extract Using GC–MS and Titration. JPS 2025, 8, 2662-2673.