Automated solid-phase extraction of opiates from urine (I).

ABSTRACT

The extraction of morphine and codeine in urine by C18 bonded-phase columns was studied using a fully automated solid-phase extraction system. Extracts of urine were analysed by a high-performance liquid chromatographic method. Recovery of the opiates depends on the urine pH, and the choice of washing solvents and eluent. Studies were carried out on the optimisation of eluent volume by establishing a recovery-time profile for the elution process. Regenerated C18 bonded-phase columns could be re-used with negligible carry-over and insignificant recovery loss. An automated extraction procedure was developed for morphine and codeine in urine with absolute recoveries exceeding 80%.