Quantitation and confirmation of six sulphonamides in meat by liquid chromatography–mass spectrometry with photodiode array detection

Multiresidue analysis of six sulphonamides (SAs) (sulphadiazine, sulphadimidine, sulphamonomethoxine, sulphamethoxazole, sulphadimethoxine, and sulphaquinoxaline) in meat (beef, pork, and chicken) using liquid chromatography (LC)–mass spectrometry (MS) with photodiode array (PDA) detection is presented. The sample preparation is carried out by normal-phase matrix solid-phase dispersion (MSPD) with an ethanol solution. The LC–MS determination is performed using a Mightysil RP-4 GP column and an isocratic mobile phase of 0.3% (v/v) acetic acid solution (pH 3.4, in water)–ethanol (83:17, v/v) with an atmospheric pressure chemical ionization (APCI) MS on positive-ion mode. Average recoveries spiked at 0.05–0.5 ppm for each drug were higher than 90% with relative standard deviations between 1% and 6%. In all the processes, no toxic solvents were used at all.