Development, Validation, and Application of a Novel Multi-Analyte High-Resolution Gas Chromatography-Mass Spectrometry (HRGC-MS) Method for the Quantification of Opioid Derivatives, Including Heroin, Morphine, and Fentanyl, in Biological Matrices with Enh. JOC. 2025;24(4s):1035-1048. doi:10.64149/J.Carcinog.24.8s.1035-1048