SIMULTANEOUS DETERMINATION OF XYLAZINE AND ITS MAJOR METABOLITE, 2,6-DIMETHYLANILINE, IN BOVINE AND SWINE KIDNEY BY LIQUID-CHROMATOGRAPHY

A liquid chromatographic (LC) method is described for the simultaneous determination of xylazine (XY) and its major metabolite, 2,6-dimethyl aniline (2,6-DMA), in bovine and swine kidney in the 25-100 ppb range. XY and 2,6-DMA are extracted from kidney with chloroform, followed by cleanup on an acidic Celite 545 column. A muBondapak phenyl column is used for LC separation with UV determination at 225 nm. The mobile ph ase is a mixture of acetonitrile, water, sodium acetate, and acetic ac id. Mean recoveries from bovine kidney were 78.3% for XY, with a stand ard deviation (SD) of 7.45 and a coefficient of variation (CV) of 9.51 %, and 87.2% for 2,6-DMA, with an SD of 8.38 and a CV of 9.61 %. Mean recoveries from swine kidney were 80.8% for XY, with an SD of 5.92 and a CV of 7.33%, and 86.7% for 2,6-DMA, with an SD of 6.16 and a CV of 7.10%.