ABSTRACT
An automated liquid chromatographic method for the determination of omeprazole and two metabolites in plasma and urine is described. It utilizes the Technicon Fully-Automated-Sample-Treatment-LC system (FAST(R)-LC). Sample preparation is achieved by air-segmented continuous-flow providing solvent extraction, evaporation to dryness and reconstitution before injection onto a reversed-phase column. The compounds are separated by isocratic or gradient elution with acetonitrile-phosphate buffer mobile phases and quantified by UV-measurements at 302 nm. The limit of determination (relative standard deviation 10-15%) is 50 nmol l(-1) in plasma (800 microl) and 200 nmol l(-1) in urine (200 microl). The sample capacity is six or three samples per hour, depending on the elution mode.
ABSTRACT
Omeprazole and three of its metabolites, the sulfone (H 168/66), the sulfide (H 168/22) and the hydroxy metabolite (H 195/80), are determined in plasma and urine by liquid chromatographic methods. The compounds are extracted from the biological sample and the extract is subjected to liquid chromatographic separation, either directly or after evaporation of the organic solvent and dissolution in a polar phase. The effluent from the column is UV-monitored at 302 nm and the quantitative evaluation performed by electronic integrator. Both a method with manual sample work-up and automatic injection and a fully automated system, Technicon FAST-LC, have been employed for the analyses. More than 25 000 samples have been assayed so far by these two methods.
