COMPARISON OF FLOW-INJECTION THERMOSPRAY MS MS AND LC THERMOSPRAY MS/MS METHODS FOR DETERMINATION OF SULFONAMIDES IN MEAT AND BLOOD/

Two quantitative analysis methods for measuring sulfonamides in spiked meat and blood samples are described. Both methods are based on therm ospray tandem mass spectrometry. One method includes on-line liquid ch romatographic separation before the tandem mass analysis and the other is based on now injection. The extraction procedure is a simple metho d where blood or minced meat is shaken with ethylacetate. The ethyl ac etate phase is isolated and evaporated to dryness. The chromatographic ally separated sulfonamides are mass analyzed by detection of the char acteristic fragment ion, m/z = 156, which all sulfonamides share. The mass analysis of the flow-injected samples is made by parent ion detec tion. The analysis method for the chromatographically separated compou nds has slightly lower detection limits for the sulfonamides compared to the flow injection method. But the detection Limits for all compoun ds are well below the maximum residue limit of 50 ppb in meat. The flo w injection method can analyze 40-60 extracts/h and show no contaminat ion or sensitivity problems even after more than 1000 analyses of crud e extracts. Both methods provide good sensitivity, some quantitative a ccuracy, and acceptable detection Limits.