FAST ANALYSIS OF CLENBUTEROL AND BETA-AGONIST RESIDUES IN BOVINE URINE USING GC-MS

A rapid and sensible analytical method for analysing clenbuterol and o ther beta-agonist residues in bovine urine is proposed. The method is based on solid phase extraction using porous silica derivatized with h ydrofobic groups (C-18), derivatization of the extracted solutes with a BSTFA/TMCS mixture and analysis of the derivatives by gas chromatogr aphy - mass spectrometry using positive electron impact (EI) and selec ted ion monitoring (SIM). The recovery of clenbuterol, mabuterol and c imaterol is > 90% with coefficient variation (CV) values between 3.0 a nd 3.5%. The detection limit for clenbuterol is 0.1 ppb with a CV valu e of 8% for SIM analysis.