Rapid high-throughput assay for the measurement of amino acids from microdialysates and brain tissue using monolithic C_(18)-bonded reversed-phase columns

摘要

A rapid precolumn high-performance liquid chromatography method based on fluorescence detection has been developed for the measurement of multiple amino acids from both ex vivo and in vivo biological samples using monolithic C_(18) columns. A mixture of 18 primary amino acids were derivatised with napthalene-2,3-dicarboxaldehyde (NDA) in the presence of cyanide. The resulting isoindole derivatives were resolved within 10 min using a linear binary gradient elution profile with Rs values in the range 1.2–9.0. The limit of detection (LOD) was found to be between 6.0 and 60 fmol for 5 μl injection with a signal to noise ratio of 3:1. The NDA derivatives were found to be stable for 9 h at 4 °C. This assay has been employed for the rapid analysis of amino acids from brain tissue and microdialysis samples. Examples of application of the method are given.