Comparison of separation conditions and ionization methods for the liquid chromatography–mass spectrometric determination of sulfonamides

The effects of the type and concentration of buffer, composition of the mobile phase and the ionization mode, used for the separation and detection of sulfonamides with LC–MS, were studied. Five typical sulfonamides were selected as target compounds and beef meat was selected as a matrix sample. For the separation of sulfonamides, 0.05 M NH4Ac in 13–15% aqueous acetonitrile, APCI ionization was more effective than ESI with regard to separation efficiency and the detection sensitivity.