2,5-Dimethyl-1H-pyrrole-3,4-dicarbaldehyde as a precolumn derivatization reagent for HPLC/UV detection of amino acids

The use of 2,5-dimethyl-1H-pyrrole-3,4-dicarbaldehyde as a precolumn derivatization reagent for HPLC analysis of amino acids is proposed. The compound reacts under mild conditions (10 min at ambient temperature) with primary amino groups. The derivatization conditions to obtain quantitative reaction were optimised by considering different parameters (temperature, pH and reagent concentration) using l-Val as the model compound. The synthesized l-Val derivative was characterized by 1H NMR and UV. The derivatives of 19 amino acids were separated by reversed-phase HPLC and detected at λ = 320 nm. The method was applied successfully to the qualitative and quantitative analysis of commercial polyamino acid preparations.