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

Area of Science:

• Analytical Chemistry
• Metabolomics
• Biochemistry

Background:

• Capillary electrophoresis-mass spectrometry (CE-MS) is theoretically well-suited for analyzing charged metabolites in metabolomics.
• However, its application is limited by low concentration sensitivity due to post-column dilution with sheath liquid (SL).

Purpose of the Study:

• To investigate the performance of a flow-through microvial (MV)-assisted CE-MS interface for cationic metabolomics.
• To compare the sensitivity and limit of detection (LOD) of the MV interface against the traditional SL-assisted interface.

Main Methods:

• A metabolite mix of 45 cationic metabolites was used for evaluation.
• The MV-assisted CE-MS interface was compared with the SL-assisted CE-MS interface.
• The method was demonstrated on single zebrafish embryos.

Main Results:

• The MV-assisted interface significantly improved CE-MS performance, increasing sensitivity over threefold.
• The LOD was decreased more than fivefold with the MV interface.
• Analysis of zebrafish embryos revealed twice as many molecular features compared to SL-assisted CE-MS, with several identified.

Conclusions:

• The flow-through microvial (MV) interface substantially enhances CE-MS sensitivity and detection capabilities for metabolomics.
• This improved interface offers greater metabolome coverage, particularly for volume-limited biological samples like zebrafish embryos.