Publications by Ali H Abikhodr

Combining Liquid Chromatography and Cryogenic IR Spectroscopy in Real Time for the Analysis of Oligosaccharides

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr

While the combination of liquid chromatography (LC) and mass spectrometry (MS) serves as a robust approach for oligosaccharide analysis, it has difficulty distinguishing the smallest differences between isomers. The integration of infrared (IR) spectroscop ...

Amer Chemical Soc2024

Identification of human milk oligosaccharide positional isomers by combining IMS-CID-IMS and cryogenic IR spectroscopy

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Vasyl Yatsyna

High-resolution ion mobility spectrometry (IMS) coupled with cryogenic infrared spectroscopy has proven to be a powerful technique for the identification of oligosaccharides. However, the need for an extensive database, combined with the scarcity of pure s ...

2023

Advancing Glycan Analysis: Cryogenic Ion Spectroscopy for Database-Driven Identification

Ali H Abikhodr

Glycans play a pivotal role in both physiological processes; however, the field of glycobiology remains relatively understudied within biochemistry. The intricate complexity of glycans, coupled with their abundance of isomeric forms, presents formidable ch ...

EPFL2023

New Approach for the Identification of Isobaric and Isomeric Metabolites

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Teun Van Wieringen

The structural elucidation of metabolite molecules is important in many branches of the life sciences. However, the isomeric and isobaric complexity of metabolites makes their identification extremely challenging, and analytical standards are often require ...

2023

Using Hadamard Transform Multiplexed IR Spectroscopy Together with a Segmented Ion Trap for the Identification of Mobility-Selected Isomers

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Vasyl Yatsyna

The high isomeric complexity of glycans makes them particularly difficult to analyze. While ultra-high-resolution ion mobility spectrometry(IMS) can offer rapid baseline separation of many glycan isomers,their unambiguous identification remains a challengi ...

2023

High-Throughput Multiplexed Infrared Spectroscopy of Ion Mobility-Separated Species Using Hadamard Transform

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Vasyl Yatsyna

Coupling vibrational ion spectroscopy with highresolution ion mobility separation offers a promising approach for detailed analysis of biomolecules in the gas phase. Improvements in the ion mobility technology have made it possible to separate isomers with ...

AMER CHEMICAL SOC2022

Identifying Mixtures of Isomeric Human Milk Oligosaccharides by the Decomposition of IR Spectral Fingerprints

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Ali H Abikhodr, Vasyl Yatsyna

The analysis of glycans presents a significant challenge that arises from their isomeric heterogeneity. While high-resolution ion mobility spectrometry (IMS) has shown the ability to resolve subtly different glycan isomers, their unambiguous assignment rem ...

2021

Unravelling the structures of sodiated beta-cyclodextrin and its fragments

Thomas Rizzo, Robert Paul Pellegrinelli, Eduardo Carrascosa Casado, Ali H Abikhodr

We present cryogenic infrared spectra of sodiated beta-cyclodextrin beta-CD + Na, a common cyclic oligosaccharide, and its main dissociation products upon collision-induced dissociation (CID). We characterize the parent ions using high-resolution ion ...

2021

Using SLIM-Based IMS-IMS Together with Cryogenic Infrared Spectroscopy for Glycan Analysis

Thomas Rizzo, Ahmed Ben Faleh, Natalia Yalovenko, Stephan Warnke, Priyanka Bansal, Ali H Abikhodr, Vasyl Yatsyna

The isomeric heterogeneity of glycans poses a great challenge for their analysis. While combining ion mobility spectrometry (IMS) with tandem mass spectrometry is a powerful means for identifying and characterizing glycans, it has difficulty distinguishing ...

2020

Analyzing glycans cleaved from a biotherapeutic protein using ultrahigh-resolution ion mobility spectrometry together with cryogenic ion spectroscopy

Thomas Rizzo, Natalia Yalovenko, Priyanka Bansal, Ali H Abikhodr, Vasyl Yatsyna

Glycans covalently attached to protein biotherapeutics have a significant impact on their biological activity, clearance, and safety. As a result, glycosylation is categorized as a critical quality attribute that needs an adequate analytical approach to gu ...

2020