Analysis of N-acetylated hexosamine monosaccharides by ferrocenyl boronation and tandem electrospray ionization mass spectrometry.

A tandem electrospray mass spectrometric (MS(n)) technique for the analysis of N-acetylated hexose carbohydrates using ferrocene boronate (F(c)Bor) derivatization was developed. The biologically important N-acetyl hexosamines can be readily distinguished utilizing this technique. The analysis is made possible by utilizing the inherent electrochemical properties of the electrospray device to produce oxidized, pre-formed single-electron ferrocenyl ions in a non-aqueous solvent system. The electrospray device was modified using a custom built cell consisting of concentric stainless steel tubes, which produced an enhanced signal for the molecular ion of each analyte species. The MS(2) spectra derived from isomeric populations of ferrocenyl boronic esters of these carbohydrates when generated under the same conditions possessed features unique to each sugar allowing easy differentiation between a number of N-acetyl hexosamine isomers. Copyright 2000 John Wiley & Sons, Ltd.