CE-MS For Metabolomics Research Articles

Inside Front Cover: CE‐MS for metabolomics: Developments and applications in the period 2016–2018

Inside Front Cover: CE‐MS for metabolomics: Developments and applications in the period 2016–2018

CE-MS for metabolomics: Developments and applications in the period 2016-2018.

In the field of metabolomics, CE‐MS is now recognized as a strong analytical technique for the analysis of (highly) polar and charged metabolites in a wide range of biological samples. Over the past few years, significant attention has been paid to the design and improvement of CE‐MS approaches for (large‐scale) metabolic profiling studies and for establishing protocols in order to further expand the role of CE‐MS in metabolomics. In this paper, which is a follow‐up of a previous review paper covering the years 2014–2016 (Electrophoresis 2017, 38, 190–202), main advances in CE‐MS approaches for metabolomics studies are outlined covering the literature from July 2016 to June 2018. Aspects like developments in interfacing designs and data analysis tools for improving the performance of CE‐MS for metabolomics are discussed. Representative examples highlight the utility of CE‐MS in the fields of biomedical, clinical, microbial, and plant metabolomics. A complete overview of recent CE‐MS‐based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings and MS detection mode. Finally, some general conclusions and perspectives are given.

Strategies Involving Mass Spectrometry Combined with Capillary Electrophoresis in Metabolomics.

This chapter focuses on the important contribution of CE-MS in metabolomics, describing the nature of CE-MS coupling and the technical improvements that have led to the interfaces used in modern instrumentation. Moreover, it will discourse how the variety of electrolyte compositions and additives, which has conferred CE the exceptional selectivity of its multiple separation modes, has been handled to allow interfacing with MS without compromising ionization efficiency and the spectrometer integrity. Finally, the methodologies of CE-MS in current use for metabolomics will be discussed in detail. To verify the scope of CE-MS in clinical metabolomics, a myriad of representative applications has been compiled.

CE-MS for metabolomics: Developments and applications in the period 2014-2016.

CE–MS can be considered a useful analytical technique for the global profiling of (highly) polar and charged metabolites in various samples. Over the past few years, significant advancements have been made in CE–MS approaches for metabolomics studies. In this paper, which is a follow‐up of a previous review paper covering the years 2012–2014 (Electrophoresis 2015, 36, 212–224), recent CE–MS strategies developed for metabolomics covering the literature from July 2014 to June 2016 are outlined. Attention will be paid to new CE–MS approaches for the profiling of anionic metabolites and the potential of SPE coupled to CE–MS is also demonstrated. Representative examples illustrate the applicability of CE–MS in the fields of biomedical, clinical, microbial, plant, and food metabolomics. A complete overview of recent CE–MS‐based metabolomics studies is given in a table, which provides information on sample type and pretreatment, capillary coatings, and MS detection mode. Finally, general conclusions and perspectives are given.

CE-MS in metabolomics: status quo and the way forward.

CE-MS in metabolomics: status quo and the way forward.

Capillary electrophoresis‐mass spectrometry using a flow‐through microvial interface for cationic metabolome analysis

The application of CE-MS in the field of metabolomics is underrepresented, even though it is in principle highly suited for the analysis of small charged compounds, as many metabolites are. Moreover, a robust coupling, using the sheath liquid (SL)-assisted interface was already presented more than a decade ago. A lack of concentration sensitivity is often mentioned as a reason for the underrepresentation of CE-MS in metabolomics. This is caused by postcolumn dilution of the sample with SL, which is typically delivered at a flow rate of 1-10 μL/min. In this study, we investigated the performance of the flow-through microvial (MV) assisted CE-MS interface for cationic metabolomics. With this interface, only a little liquid is added postcolumn, that is, typically 100-500 nL/min. For the evaluation, we used a metabolite mix comprising 45 important cationic metabolites and compared the sensitivity and LOD of both devices. The performance of the CE-MS system was significantly improved by using the MV-assisted interface; the sensitivity was increased more than three times and the LOD decreased more than five times. Then, we analyzed single zebrafish embryos to demonstrate the method on a volume-limited biological sample. In comparison with SL-assisted CE-MS, twice as many molecular features were found, of which several could be identified. These results demonstrate the good potential of the MV interface for enhancing the coverage of the metabolome.

CE‐MS for metabolomics: Developments and applications in the period 2008–2010

This review provides an update of the state-of-the-art of CE-MS for metabolomic purposes, covering the scientific literature from July 2008 to June 2010. This review describes the different analytical aspects with respect to non-targeted and targeted metabolomics and the new technological developments used in CE-MS for metabolomics. The applicability of CE-MS in metabolomics research is illustrated by examples of the analysis of biomedical and clinical samples, and for bacterial and plant extracts. The relevant papers on CE-MS for metabolomics are comprehensively summarized in a table, including, e.g. information on sample type and pretreatment, and MS detection mode. Future considerations such as challenges for large-scale and (quantitative) clinical metabolomics studies and the use of sheathless interfacing and different ionization techniques are discussed.

CE‐MS in metabolomics

An overview of the use of CE-MS in the field of metabolomics is provided. Metabolomics is concerned with the comprehensive analysis of endogenous low-molecular-weight compounds in biological samples. CE-MS has demonstrated to be a powerful technique for the profiling of polar metabolites in biological samples. This review covers the use of various CE separation modes, capillary coatings, MS analyzers, sample preparation techniques, and data analysis methods used in CE-MS for metabolomics. The applicability of CE-MS in metabolomics research is illustrated by giving examples of the analysis of bacterial extracts, plant extracts, urine, plasma, and cerebrospinal fluid samples. The relevant CE-MS metabolomics studies published between 2000 and 2008 are presented in tabular form, including information on sample type and pretreatment and MS detection mode. Future developments with regard to the use of alternative ionization techniques, the use of coupled separation systems and the potential of microchip CE systems for metabolomics are discussed.