Detection and identification of pyrovalerone and its hydroxylated metabolite in the rat.

Detection and identification of pyrovalerone and its metabolite, a hydroxylated product, are described. Their identities were confirmed by comparing their mass spectra and gas chromatographic retention times with those of the synthetic standards. The analytical method of pyrovalerone and its metabolite in biological samples was developed. The detection limit of the two compounds was 5 ng/mL, and the standard curves were linear in the concentration range of 10-5000 ng/mL. The single dose kinetics of pyrovalerone and the metabolite in rat urine and plasma were studied (n = 3). The calculated first half-life time of pyrovalerone in rat plasma was 0.34 h, and the second half-life time was 1.50 h. The half-life time of the metabolite was 0.39 h. The two products were detected in rat urine up to 18 h after a single oral administration and are suggested as screening target compounds in dope analysis.