Screening, confirmation, and quantification of sulphonamide residues in pig kidney by tandem mass spectrometry of crude extracts

Collisionally activated dissociation mass spectra, observed with a hybrid tandem instrument, of the chemical ionization protonated molecular ions of sulphonamide drugs have been used as the basis of a rapid screening procedure for these drugs in crude extracts of pig's kidney by scanning to detect the parents of a characteristic daughter fragment. Extracts were introduced without chromatography by a moving belt interface. Detection limits of 0.1 mg/kg were achieved. Confirmation was made by obtaining daughter ion spectra of the protonated molecular ions. Multiple reaction monitoring with a stable isotope analogue as internal standard permitted the quantification of targeted compounds with high sensitivity and precision.