Determination of morphine in process streams using flow-injection analysis with chemiluminescence detection

Flow analysis methodology is presented for the determination of morphine in process streams. Detection is achieved by monitoring the resultant chemiluminescence (CL) emission from the reaction of morphine and acidic potassium permanganate in the presence of tetraphosphoric acid. Calibration graphs are linear over two orders of magnitude of concentration with a detection limit (3:1 signal-to-noise ratio) of 5×10-8 M and relative standard deviation of 0.4% at 1.4×10-4 M. Interferences from other alkaloids in the extract are negligible due either to lack of CL response or to low concentrations of the concomitants. Some discussions regarding the nature of the emitting species is presented based on CL spectra from morphine and other structurally related alkaloids. The analytical results obtained on process samples compared most favourably with results from a validated liquid chromatographic method.