• • LC-MS/MS methods achieve sub-ng/mL limits of detection (e.g., 0.1 ng/mL) for non-fentanyl opioids in whole blood, enabling detection of low-dose exposures critical for forensic casework and wastewater-based epidemiology.
• • Solid-phase extraction (SPE) using mixed-mode sorbents yields recoveries exceeding 85% for a panel of 24 fentanyl analogs and metabolites, reducing matrix effects and improving method robustness for routine toxicology screening.
• • Multiplex assays can simultaneously quantify up to 38 opioids and metabolites in a single run, with total analysis times under 15 minutes, enhancing throughput for high-volume laboratories.
• • The emergence of nitazene analogs, with potencies up to 10,000 times that of morphine, necessitates HRMS-based screening to differentiate isomers and ensure accurate identification, as conventional MS/MS may produce false negatives.