Details

Autor(en) / Beteiligte

• van Mever, Marlien
• Segers, Karen
• Drouin, Nicolas
• Guled, Faisa
• Heyden, Yvan Vander
• Van Eeckhaut, Ann
• Hankemeier, Thomas
• Ramautar, Rawi

Titel

Direct profiling of endogenous metabolites in rat brain microdialysis samples by capillary electrophoresis-mass spectrometry with on-line preconcentration

Ist Teil von

• Microchemical journal, 2020-07, Vol.156, p.104949, Article 104949

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2020

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •CE-MS method for direct metabolic profiling of rat brain microdialysis samples•On-line preconcentration employed to further improve CE-MS detection sensitivity•A range of endogenous metabolites reliably quantified in rat brain microdialysis samples Metabolic profiling of body fluids from small animal models is often used in (translational) biological studies in order to obtain insight into the underlying molecular mechanisms of (complex) diseases. An example is the use of brain microdialysis samples from rats to study neurological disorders by means of a metabolomics approach. From an analytical point of view, the profiling of (endogenous) metabolites in rat brain microdialysates is challenging because of the limited sample volume for both sample preparation and injection, notably in longitudinal studies. In this work, we have assessed the analytical performance of capillary electrophoresis-mass spectrometry (CE-MS) for the direct profiling of endogenous metabolites in rat brain microdialysates, i.e. without using any sample preparation or derivatization. An on-line preconcentration procedure with sample stacking, which was fully compatible with the high-salt concentration in microdialysates, was used to significantly improve the detection sensitivity of the CE-MS method for metabolic profiling. A response surface methodology, applying a Box-Behnken design, was considered to determine the optimal conditions for preconcentration. A linear response (R2>0.99) for selected metabolites in the concentration range from 0.05 to 10 µM was obtained in perfusate samples. Interday RSD values for peak area and migration time were 2.6-19% and below 3.8%, respectively. Limits of detection ranged from 11 to 284 nM when employing an injection volume of about 291 nL, corresponding to 17% of the total capillary volume. The utility of the CE-MS approach was demonstrated by the direct profiling of endogenous metabolites in rat brain microdialysates. At least 48 compounds could be analyzed of which 25 were provisionally identified and quantified.