Determination of Morphine by Capillary Zone Electrophoresis Immunoassay Combined with Laser‐Induced Fluorescence Detection

Abstract A competitive immunoassay for detecting morphine in bio‐samples was established by capillary zone electrophoresis combined with laser‐induced fluorescence detection (CZE‐LIF). The antigen of morphine was labeled with isothiocyano‐fluorescein (FITC) and then incubated with morphine monoclonal antibody and samples. The linear range was 50–1000 ng/mL, which was suitable for clinical and forensic applications. The detection limit can reach 40 ng/mL, based on S/N = 2. The recoveries of morphine from serum were satisfactory.