Selective and quantitative isolation and determination of apomorphine in human plasma

A simple extraction system for the selective and quantitative isolation of apomorphine from human plasma is described. Apomorphine and N-n-propylnorapomorphine were isolated by complex formation between a borate group and the diol group of the apomorphines in an alkaline medium, this in combination with ion-pair formation. The reproducibility and linearity of this extraction method combined with high-performance liquid chromatography with electrochemical detection is excellent. The absolute mean recovery of apomorphine was 100%, the recovery of N-n-propylnorapomorphine was 98%. The detection limit of apomorphine in human plasma in the described system is approximately 0.5 ng/ml.