Development of an Automated On-line Hyphenation of Capillary Electrophoresis with Multicollector ICP-MS for Species-specific Isotopic Analysis of Biomolecules

• Applicant: Dr. Björn Meermann
• Subject Area: Analytical Chemistry
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 440953647

Up to now, only a few studies have dealt with species-specific isotopic analysis by on-line hyphenation with MC-ICP-MS and only one with CE/MC-ICP-MS. However, this field holds great potential in varying research areas. This project will focus on the use of CE/MC-ICP-MS for the simultaneous isotopic analysis of elemental species, especially S, as it is the only target element for ICP-MS in all proteins in biological systems and is also present in peptides and smaller important biomolecules. Isotope variations of S in biomolecules could be used for the elucidation and tracing of biological processes, as well as help diagnosing diseases and monitoring treatment progress. Furthermore, the proposed method will foster the development of certified reference materials in bioresearch and support metrology activities in this research area.Therefore, the main objectives of this work are:PI) The development of a CE/MC-ICP-MS hyphenation. Automation will be implemented as much as possible, so that single samples and sequences can be analyzed without supervision of an operator. For transient data evaluation, a template in a suitable software (MS Excel, Origin) will be prepared, where most of the evaluation processes are executed automatically.PII) For validation purposes, a suitable species-specific secondary reference standard will be prepared and characterized against a sulfur iRM by off-line separation and analysis with multicollector-ICP-MS. The secondary standard will then be applied for the validation of the newly developed CE/MC-ICP-MS hyphenation. It may also be used as a bracketing standard since isotopic iRMs are not only very expensive but also of limited availability.PIII) Adaption of the developed method to ICP-ToF-MS and subsequent comparison of CE/MC-ICP-MS and CE/ICP-ToF-MS for isotopic analysis in short transient signals.PIV) The application of the developed CE/MC-ICP-MS and/or CE/ICP-ToF-MS method to biomolecules in real biological samples. For a start, methionine, cysteine and taurine can be used as more simple target molecules before advancing to peptides like glutathione, smaller proteins like metallothionein and finally larger proteins like human serum albumin.

• DFG Programme: Research Grants
• Co-Investigator: Dr. Jochen Vogl