Characterization of Isomeric Sulfonamides Using Capillary Zone Electrophoresis Coupled with Nano-Electrospray Quasi-MS/MS/MS

✍ Scribed by Bateman, Kevin P.; Locke, Steven J.; Volmer, Dietrich A.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 449 KB
• Volume: 32
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/(sici)1096-9888(199703)32:3<297::aid-jms485>3.0.co;2-6

✦ Synopsis

The application of capillary electrophoresis/nano-electrospray mass spectrometry to the multi-residue analysis of a large number of sulfonamide antibiotics in milk samples is reported. Tandem mass spectrometric (MS/MS) techniques including precursor ion scans and multiple reaction monitoring were used to identify residues at the low ppb level to the ppt level. Three pairs of isomeric sulfonamides were targeted that di †er only in the positions of the nitrogen and oxygen atoms in the heterocyclic aromatic rings of the molecules. Conventional MS/MS analysis yielded no isomer-speciÐc ions. Therefore, a quasi-MS/MS/MS method was applied to overcome these limitations. In-source collision-induced dissociation (CID) was used as a quasi-MS/MS stage to generate ions arising from the heteroaromatic amine moiety. In a second MS/MS step these ions were isolated and made to undergo CID in the collision quadrupole to yield isomer-speciÐc ions. Examples of the application of these methodologies to the analysis of milk extracts are illustrated.