Publications de Ahmed Ben Faleh

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

Multistage Ion Mobility Spectrometry Combined with Infrared Spectroscopy for Glycan Analysis

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal

The structural complexity of glycans makes their characterization challenging, not only because of the presence of various isomeric forms of the precursor molecule but also because the fragments can themselves be isomeric. We have recently developed an IMS ...

2023

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

Device, system, and method for ion fragmentation by use of an ion mobility device and messenger tagging

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke

A device for fragmenting ions by collision induced dissociation, the device intended to be used together with a planar ion mobility apparatus, the device including a first conductive grid having a plurality of first openings, the first conductive grid conf ...

2023

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

Identification of N-glycan positional isomers by combining IMS and vibrational fingerprinting of structurally determinant CID fragments

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal

While glycans are present on the surface of cells in all living organisms and play key roles in most biological processes, their isomeric complexity makes their structural characterization challenging. Of particular importance are positional isomers, for w ...

ROYAL SOC CHEMISTRY2022

A method and system to build an ir fingerprint database for the structural identification of biomolecules

Thomas Rizzo, Ahmed Ben Faleh, Stephan Warnke, Priyanka Bansal, Robert Paul Pellegrinelli

A method, system, and computer-readable medium for identifying and creating a database of isomers and isobars of molecules including the steps of performing isomer or isobar separation on molecules to obtain separate isomeric or isobaric molecules, measuri ...

2022

A New Approach for Identifying Positional Isomers of Glycans Cleaved from Monoclonal Antibodies

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

SWISS CHEMICAL SOC2022

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