title: Determination of acetaldehyde in fuel ethanol by high-performance liquid chromatography with electrochemical detection.
abstract: The cyclic voltammetric behavior of acetaldehyde and the derivatized product with 2,4-dinitrophenylhydrazine (DNPHi) has been studied at a glassy carbon electrode. This study was used to optimize the best experimental conditions for its determination by high-performance liquid chromatographic (HPLC) separation coupled with electrochemical detection. The acetaldehyde-2,4-dinitrophenylhydrazone (ADNPH) was eluted and separated by a reversed-phase column, C18, under isocratic conditions with the mobile phase containing a binary mixture of methanol/LiCl(aq) at a concentration of 1.0 x 10(-3) M (80:20 v/v) and a flow rate of 1.0 mL min(-1). The optimum condition for the electrochemical detection of ADNPH was +1.0 V vs. Ag/AgCl as a reference electrode. The proposed method was simple, rapid (analysis time 7 min) and sensitive (detection limit 3.80 microg L(-1)) at a signal-to-noise ratio of 3:1. It was also highly selective and reproducible [standard deviation 8.2% +/- 0.36 (n = 5)]. The analytical curve of ADNPH was linear over the range of 3-300 mg L(-1) per injection (20 microL), and the analytical recovery was > 99%.
authors.affiliation: UNESP, Department of Analytical Chemistry, Rua Prof Francisco Degni s/n, Quitandinha, 14800-900, Araraquara-SP, Brazil.
authors.forename: Adelir A
authors.initials: AA
authors.lastname: Saczk
authors.forename: Leonardo L
authors.initials: LL
authors.lastname: Okumura
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: De Oliveira
authors.forename: Maria Valnice B
authors.initials: MV
authors.lastname: Zanoni
authors.forename: Nelson R
authors.initials: NR
authors.lastname: Stradiotto