Determination of apomorphine in plasma by selected ion monitoring.

A selected ion monitoring assay for apomorphine using N-n-propylnorapomorphine as an internal standard is described. The molecular ions of the TMS derivatives of apomorphine (m/z 411) and N-n-propylnorapomorphine (m/z 439) were assayed simultaneously by selected ion monitoring. Sensitivity was 30 ng per ml plasma. The results obtained by plasma apomorphine concentration time course study in rats suggested that this method was applicable to pharmacokinetic studies for apomorphine.