Selected ion monitoring of apomorphine in whole rat brain

Mass fragmentography was used for quantitation of apomorphine in whole rat brain. Following extraction with 0.45 N perchloric acid, the components were derivatized to the O,O-bis(trimethylsilyl) (TMS) derivatives with N,O-bis(trimethylsilyl)trifluoroacetamide at 30 degrees C. The molecular ions of the TMS derivatives of apomorphine (m/z 411) and N-n-propylnorapomorphine (m/z 439), as an internal standard, were assayed simultaneously by selected ion monitoring. Total chromatography time is 5 min. By this method 50 ng/ml can be determined with a coefficient of variation of 12.0%. Application of the method to apomorphine disposition study in whole rat brain was demonstrated.