A METHOD FOR THE ANALYSIS OF SOME NEUROLEPTICS AND CARAZOLOL IN PORK KIDNEYS

A method is described for the analytical determination of the neuroleptics azaperone (plus its metabolite azaperol), acetylpromazine, propionylpromazine, chlorpromazine and the beta-blocking agent carazolol in pork kidneys. These compounds may be used illegally to calm pigs during their transport to the abattoir. The kidney samples (plus atosil as an internal standard) are incubated with NaOH (90 degrees C, 60 min); the rather fluid samples are extracted with diethylether. The separation of interfering compounds in the extracts is achieved on a silica gel column. The remaining interfering compounds are removed with ether after acidification of the eluted material. After alkalization of the aqueous solution, the drugs are extracted with ether and applied to a Symmetry RP18 column (mobile phase: acetate buffer solution pH 4.5/acetonitrile/tetrahydrofurane, 65/30/10 by volume by HPLC. Recovery in spiked samples of pork kidneys (recovery of 50 mu g/kg, carazolol 5 mu g/kg) was between 71.5% (for propionylpromazine) and 88% (for azaperol). The method was verified on samples of treated pigs.