VALIDATION OF A METHOD FOR THE DETERMINATION OF SALBUTAMOL IN ANIMAL URINE BY GAS-CHROMATOGRAPHY MASS-SPECTROMETRY AND ITS APPLICATION TO TREATED LAMB SAMPLES

The validation of a fast, reliable, and specific method for the screen ing, confirmation, and determination of salbutamol in urine with (tota l) and without (free fraction) a hydrolysis step was developed. Sample urine from different animal species was extracted using Bond Elut cer tify columns. The described method includes enzymatic hydrolysis, soli d-phase extraction, trimethyl silyl derivatives formation, and final d etermination and identification by gas chromatography-mass spectrometr y. Good linearity was obtained between 2 and 40 mu g/L. The recovery w as 85%, and the limit for identifcation of salbutamol, based on the si multaneous detection of four diagnostic ions, was established at 2 mu g/L. Repeatability and within-laboratory reproducibility were 4.4% and 7.1% (percent standard deviation), respectively. Salbutamol was found mainly in the conjugated form in lamb urine (99%). Total salbutamol c oncentration in lamb urine was compared with those obtained by ELISA. (C) 1996 John Wiley & Sons, Inc.