Abstract
Oligosaccharides serve many roles in extant life and may have had a significant role in prebiotic chemistry on the early Earth. In both these contexts, the structural and isomeric diversity among carbohydrates presents analytical challenges necessitating improved separations. Here, we showcase a chemical derivatization approach, where 3-carboxy-5-nitrophenylboronic acid (3C5NBA) is used to label vicinal hydroxyl groups, amplifying the structural difference between isomers. We explore the applicability of state-of-the-art ion mobility - mass spectrometry (IM-MS) instrumentation in the analysis of derivatized carbohydrates. In particular we focus on the resolving power required for IM separation of derivatized isomers. A recently developed cyclic ion mobility (cIM) mass spectrometer (MS) was chosen for this study as it allows for multi-pass IM separations, with variable resolving power (Rp). Three passes around the cIM (Rp ∼ 120) enabled separation of all possible pairs of four monosaccharide standards, and all but two pairs of eight disaccharide standards. Combining cIM methodology with tandem mass spectrometry (MS/MS) experiments allowed for the major products of each of the 3C5NBA carbohydrate derivatization reactions to be resolved and unequivocally identified.
1 - NSF/NASA Center for Chemical Evolution, Georgia Institute of Technology, Atlanta, GA 30332, USA. facundo.fernandez@chemistry.gatech.edu and School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.
2 - Waters Corporation, Pleasanton, CA 94588, USA.
3 - Waters Corporation, Wilmslow SK9 4AX, UK.
4 - NSF/NASA Center for Chemical Evolution, Georgia Institute of Technology, Atlanta, GA 30332, USA. facundo.fernandez@chemistry.gatech.edu and Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
Analyst. 2019 Oct 31. doi: 10.1039/c9an01584a. [Epub ahead of print]
