Liquid chromatography-diode array-mass spectrometric analysis of amino and mercapto compounds coupled with chloroimino derivatization reagent

Determination of 23 related analytes in bone marrow fluid and hippocampus of C57BL/6 mice on cerebral ischemia-reperfusion injury by HPLC-FLD

The study of brain diseases has long been of interest to researchers worldwide, and stroke is the third leading cause of death that threatens human health. At the same time, a cerebral ischemia-reperfusion injury is closely associated with high rates of disability and mortality. The conditions of the 6-Aminoquinolyl N-hydroxysccinimidyl carbamate (AQC) method for the derivatization of amino acids in the bone marrow fluid and hippocampus of C57BL/6 mice with cerebral ischemia/reperfusion injury were explored and optimized, such as the column temperature, concentration of derivatization reagents, and mobile phase concentration were investigated and optimized. The mobile phase consisted of 20 mM sodium acetate solution (phosphoric acid to adjust pH 5.0) and 60% acetonitrile solution at the flow rate of 1 mL•min^-1 . The 23 analytes were separated and determined in a gradient elution procedure; the correlation coefficient r was greater than 0.9990 in the range of 0.1-8.0 μg•mL^-1 . The results showed that the content of relevant analytes was significantly changed in the cerebral ischemia-reperfusion injury model, the method was suitable for the simultaneous determination of 23 amino acids in bone marrow fluid and hippocampus of C57BL/6 mice.

Derivatization procedures and their analytical performances for HPLC determination in bioanalysis

Derivatization, or chemical structure modification, is often used in bioanalysis performed by liquid chromatography technique in order to enhance detectability or to improve the chromatographic performance for the target analytes. The derivatization process is discussed according to the analytical procedure used to achieve the reaction between the reagent and the target compounds (containing hydroxyl, thiol, amino, carbonyl and carboxyl as the main functional groups involved in derivatization). Important procedures for derivatization used in bioanalysis are in situ or based on extraction processes (liquid-liquid, solid-phase and related techniques) applied to the biomatrix. In the review, chiral, isotope-labeling, hydrophobicity-tailored and post-column derivatizations are also included, based on representative publications in the literature during the last two decades. Examples of derivatization reagents and brief reaction conditions are included, together with some bioanalytical applications and performances (chromatographic conditions, detection limit, stability and sample biomatrix).