Thin-layer chromatographic screening method for the tranquillizers azaperone, propiopromazine and carazolol in pig tissues. 
A procedure is described for the detection of azaperone, propiopromazine and carazolol in pig muscle, liver and kidney tissue.  The method comprises extraction from an alkaline tissue homogenate with diethyl ether, followed by cleaning up and concentration of the extract on a silica gel solid-phase extraction column.  Two-dimensional thin-layer chromatography on a silica plate was used for the detection of the tranquillizers.  Detection levels were 25 micrograms kg-1 for propiopromazine, 50 micrograms kg-1 for azaperone (or its metabolite azaperol) and 125 micrograms kg-1 for carazolol.  In pigs treated with the usual doses the presence of propiopromazine and azaperol could be established in kidney tissue 8 h after administration, whilst in injection sites all three tranquillizers could be detected.