Schiff base chemiluminescence with Fenton's reagent for the determination of primary amines and amino acids

A chemiluminescence method involving Schiff base formation was studied for the determination of primary amines and amino acids. The Schiff bases derived from phenylacetaldehyde in methanol for amines and sodium bis(2-ethylhexyl)sulphosuccinate reversed micellar solution for amino acids were found to produce strong chemiluminescence when oxidized with iron(II) and hydrogen peroxide (Fenton's reagent). The chemiluminescence signal was measured by means of a flow-injection system, 100 μl of the Schiff base sample solution being injected into a methanol carrier and then mixed with the Fenton's reagent solution. The determination limits were 1.5 × 10−8 M for n-hexylamine and 1.4 × 10−7 M for alanine and the linear dynamic range was 103–105 M. The chemiluminescence mechanism is discussed briefly.