Quantification and distribution of 4-fluoroisobutyryl fentanyl (4-FiBF) in postmortem biological samples using UHPLC–QqQ-MS/MS Posted on December 13, 2021December 13, 2021 By Becky Carter Marcin Zawadzki, Olga Wachełko, Agnieszka Chłopaś-Konowałek, Paweł Szpot Forensic Toxicol.; 39; 2021 Download article Chemistry, Forensic Pathology and Medicolegal Death Investigation, Seized Drugs/Controlled Substances, Toxicology