ELECTROCATALYTIC OXIDATION AND AMPEROMETRIC DETECTION OF ALIPHATIC AND FURANIC ALDEHYDES AT A MIXED-VALENT RUTHENIUM OXIDE RUTHENIUM CYANIDE FILM ON GLASSY-CARBON ELECTRODES

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 RuCl3 and K4Ru(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 degrees 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 mmol injected (S/N = 3), respectively.