ESTIMATION OF OPIATES IN URINE BY STOPPED-FLOW FLUOROIMMUNOASSAY

The stopped-flow mixing technique was applied for the first time to th e kinetic determination of opiates. For this purpose, a method involvi ng measurement of temporal changes in the fluorescence polarization in the course of competitive immunochemical reactions of the analyte and tracer (fluorescein-labelled morphine) with the antibody was develope d. As kinetic data can be obtained in only a few seconds, this new app roach is faster than the conventional fluorescence polarization immuno assay, where measurements are carried out at the equilibrium, and lend s itself readily to application in routine analyses. The detection lim it for morphine in urine was 6.0 ng ml-1, i.e. roughly 4 times lower t han that afforded by the conventional method. The mean analytical reco very of morphine from urine was 98.5%.