Capillary Electrophoresis Mass Spectrometry as A Tool for Untargeted Metabolomics

Abstract

Highly polar and ionic metabolites, such as sugars, most amino acids, organic acids or nucleotides are not retained by conventional reversed-phase LC columns and polar stationary phases and hydrophilic-interaction LC lacks of robustness, which is still limiting their applications for untargeted metabolomics where reproducibility is a must. Biological samples such as blood, urine or even tissues include many hydrophilic compounds secreted from cells, their analysis is essential for biomarker discovery, disease progression or treatment effects. This review focuses on CE coupled to MS as a mature technique for untargeted metabolomics including sample pretreatment, types of matrices, analytical methods, applications and data treatment strategies for polar compound analysis in biological matrices. The main applications and results of CE-MS in untargeted metabolomics are discussed and presented in a tabulated format.

Mass spectrometry is a multifaceted weapon to be used in the battle against Alzheimer's disease: Amyloid beta peptides and beyond

“…A striking aspect of the latter, as already mentioned above, is the recognition that only a thorough screening of as many metabolites as possible can provide useful information on all the possible altered biomolecular pathways to go beyond the mere Aβ cascade described by the amyloid hypothesis of AD. In this perspective, in the attempt to be as comprehensive and open‐minded as possible regarding all possible cofactors that cause AD, untargeted metabolomics has been pursued alongside a targeted one that is, metabolomics investigations without predefining which metabolites should be measured. Analysis of this kind conducted in human plasma revealed alterations in 22 biochemical pathways, in particular polyamine metabolism and L‐arginine metabolism disrupted in mild cognitive impairment subjects converting to AD .…”

Phenotyping of gut microbiota: Focus on capillary electrophoresis

“…The increasing data showing the strong capabilities of CE emphasizes the need of a review in the art of gut microbiota metabolomics analysis based on this technique. Indeed, according to the literature, CE as separation technique for gut microbiota metabolomics analysis is used by less than 5% of the studies (Table ), although this number is expected to increase.…”

Assessing the suitability of capillary electrophoresis‐mass spectrometry for biomarker discovery in plasma‐based metabolomics

“…It provides complementary metabolic information compared to chromatography‐based techniques. Until now, CE coupled to MS has been utilized for metabolic profiling of a wide range of biological samples in various application fields . However, in comparison to other analytical techniques the use of CE–MS in metabolomics is still underrepresented .…”