ONLINE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC GAS-CHROMATOGRAPHIC TANDEM ION TRAP MASS-SPECTROMETRIC DETERMINATION OF LEVAMISOLE IN MILK

On-line high-performance liquid chromatography/high-resolution gas chromatography/tandem mass spectrometry, performed on a quadrupole ion trap, has been used as a rapid method for the quantification of the anthelmintic drug levamisole in raw milk extracts following a simple extraction procedure. Detection at the 0.5 pp.b. level and a linear response in the 10-0.5 p.p.b. range is demonstrated. Multiple-scan monitoring techniques have been used to acquire chemical ionization tandem mass spectra and electron impact mass spectra in a single chromatographic run.