Identification of Metabolites of Azaperone in Horse Urineǁ⊥

Abstract

Two metabolites of the tranquilizer azaperone were extracted from alkalinized horse urine after treatment with beta-glucuronidase/sulfatase from limpets (Patella vulgata). The metabolites were identified by a combination of independent chemical synthesis and GC/MS and 1H NMR analysis. The metabolites were identified as 1-(fluorophenyl)-4-[4-(5-hydroxy-2-pyridinyl)-1-piperazinyl]-1-butanol, designated as 5'-hydroxy-azaperol, and 1-(fluorophenyl)-4-[4-(5-hydroxy-2-pyridinyl)-1-piperazinyl]-1-butanone, designated as 5'-hydroxyazaperone. A TLC screening test was developed for detecting both metabolites in basic extracts of horse urine treated with beta-glucuronidase/sulfatase. The screening test was used to detect azaperone metabolites in extracts of horse urine collected for 24 h after intravenous administration of azaperone. The administration of azaperone to horses was confirmed by GC/MS identification of 5'-hydroxyazaperone and 5'-hydroxyazaperol from basic extracts of horse urine treated with beta-glucuronidase/sulfatase. The extracted metabolites were treated with bis(trimethylsilyl)acetamide to produce trimethylsilyl (TMS) ether derivatives, and mass spectra and retention times were compared to those of the synthesized metabolites treated in the same manner.

Colloidal Gold Immunochromatographic Strip Assay for the Detection of Azaperone in Pork and Pork Liver

“…Currently reported detection methods include enzyme-linked immunosorbent assay, liquid chromatography (LC)–tandem mass spectrometry, LC, and high performance LC . Although these instrumental methods have high sensitivity and accuracy, they are not suitable for the measurement of large numbers of samples.…”

“…The maximum residue limits (MRLs) of animal foods in China stipulate that the MRLs of azaperone and its metabolite azaperol in the muscle, skin and fat, liver, and kidney of pigs are 60, 60, 100 and 100 mg/kg, respectively. Currently reported detection methods include enzymelinked immunosorbent assay, 10 liquid chromatography (LC)− tandem mass spectrometry, 11 LC, 12 and high performance LC. 13 Although these instrumental methods have high sensitivity and accuracy, they are not suitable for the measurement of large numbers of samples.…”

Multiresidue analysis of tranquilizers and the beta‐blocker Carazolol in meat by liquid chromatography/tandem mass spectrometry

“…A number of gas chromatography (GC) and liquid chromatography (LC) methods have been described for the quantification of Carazolol and tranquilizers. GC coupled to commercially available thermionic sensitivity1 and mass spectometric detection2–4 has been used to quantify a number of underivatized tranquilizer residues. Trimethylsilylated Carazolol was determined by GC/MS 4.…”