Electrocatalytic oxidation and amperometric detection of aliphatic and furanic aldehydes at a mixed-valent ruthenium oxide-ruthenium cyanide film on glassy carbon electrodes

Abstract

The electrocatalytic oxidation and amperometric detection of simple and furanic aldehydes at a mixed-valent ruthenium oxide-ruthenium cyanide (mvRuO-RuCN) modified glassy carbon (GC) electrode is described. The oxoruthenium centers cross-linked with ruthenium cyanide are believed to be the electroactive surface species in acidic media. The capability of mvRuO-RuCN films to catalyze the slow electrode reaction of aldehydic compounds is illustrated in cyclic voltammetry and flowing streams amperometric detection. A sensitive quantitation of aliphatic and furanic aldehydes without the need of derivatization steps was achieved by coupling ion exclusion chromatography (IEC) with electrochemical detection, using the mvRuO-RuCN film electrode. The presence of low RuCl 3 and K 4 Ru(CN) 6 levels in the mobile phase considerably improves the response stability. Of practical importance is that this modified electrode can be used without detrimental effects at a column temperature of 60 °C. At room temperature, the detection limits of aliphatic aldehydes such as acetaldehyde, propionaldehyde, and butyraldehyde in IEC with amperometric detection (E appl = +1.08 V vs Ag/AgCl) were 1.0, 0.8, and 0.8 nmol injected (S/N = 3), respectively.