Gas chromatographic-mass spectrometric analysis of veterinary tranquillizers in urine: evaluation of method performance.

A method for analysis of veterinary tranquillizers in urine using gas chromatography-mass spectrometry (GC-MS) is described. Detection limits are 5 microg/l for ketamine, azaperone and the phenothiazines (chlor-, aceto- and propionylpromazine), 10 microg/l for haloperidol, 20 microg/l for xylazine and 50 microg/l for azaperol, recoveries for all analytes were higher than 70%. Method performance in terms of within-batch, between-days and between-analysts reproducibility was studied and found to be acceptable. Compliance with European Union criteria for confirmation of GC-MS "positive" results is evaluated and discussed.