Amperometric detection of gaseous ethanol and acetaldehyde at low concentrations on an Au–Nafion electrode

An amperometric sensor capable of detecting mixtures of ethanol and acetaldehyde in the low ppb range without the need for prior separation is described. The electrochemical cell was based on a Au sensing electrode chemically deposited onto one side of a Nafion membrane with 1 M NaOH internal electrolyte solution. The detection was achieved by applying two potentials, –450 and –290 mV vs. a saturated mercury–mercurous sulfate electrode (MSE), at which ethanol and acetaldehyde react at different rates. Under the conditions investigated, acetaldehyde oxidation was mass transport limited at both potentials, whereas the anodic current due to the oxidation of ethanol was 40% lower at the more cathodic potential. Detection limits of 2 and 1 ppb (S/N = 3) were determined for ethanol and acetaldehyde respectively when the analyte species were detected individually. Poisoning of the working electrode was not observed for concentrations of ethanol in the ppb range. Acetaldehyde oxidation was found not to affect the sensing electrode condition, even at concentrations of several tens of ppm.

[1]  H. Nakajima,et al.  Metal electrodes bonded on solid polymer electrolyte membranes (SPE)—III. CO oxidation at Au-SPE electrodes , 1986 .

[2]  G. Zauberman,et al.  Induction of Certain Aroma Volatiles in Feijoa Fruit by Postharvest Application of Acetaldehyde or Anaerobic Conditions , 1991 .

[3]  G. A. Dawson,et al.  Portable trap-sensor system for monitoring low levels of ethylene , 1997 .

[4]  J. Vázquez,et al.  Electrochemical oxidation of ethanol on Pt(hkl) basal surfaces in NaOH and Na2CO3 media , 1994 .

[5]  B. Beden,et al.  Electrocatalytic oxidation of saturated oxygenated compounds on gold electrodes , 1987 .

[6]  P. Fedkiw,et al.  Partial Oxidation of Methanol on a Metallized Nafion Polymer Electrolyte Membrane , 1992 .

[7]  M. Hitchman,et al.  Study of the Factors Affecting Mass Transport in Electrochemical Gas Sensors , 1997 .

[8]  K. Nishimura,et al.  Electrocatalytic properties of ultrafine gold particles towards oxidation of acetaldehyde and ethanol , 1993 .

[9]  E. Gonzalez,et al.  Electro-oxidation of ethanol on gold: analysis of the reaction products and mechanism , 1998 .

[10]  C. Korzeniewski,et al.  Amperometric detection with membrane-based sampling for percent-level determinations of ethanol , 1996 .

[11]  E. Ainscough,et al.  Ethylene—An unusual plant hormone , 1992 .

[12]  L. Bulhões,et al.  Oxidation of formaldehyde in an alkaline medium on a polycrystalline platinum electrode , 1992 .

[13]  O. Enea.  On the electrocatalytic oxidation of methanol vapors at Au-nafion electrodes , 1987 .

[14]  C. Forney,et al.  Volatile compounds produced by broccoli under anaerobic conditions , 1991 .

[15]  P. Millet,et al.  A solid polymer electrolyte-based ethanol gas sensor , 1996 .

[16]  A. Sammells,et al.  Gas‐Phase CO 2 Reduction to Hydrocarbons at Metal/Solid Polymer Electrolyte Interface , 1990 .

[17]  Peter C. Hauser,et al.  Amperometric Sensor for Monitoring Ethylene , 1997 .

[18]  Ingemar Lundström,et al.  Ethylene production from fruits measured by a simple field-effect structure and compared with a gas chromatographic method , 1990 .

[19]  P R Warburton,et al.  Amperometric gas sensor response times. , 1998, Analytical chemistry.

[20]  L. Rodríguez-Sinobas,et al.  Physiology and Prediction of Fruit Tolerance to Low-oxygen Atmospheres , 1991 .