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

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