title: Rapid and sensitive method for the determination of acetaldehyde in fuel ethanol by high-performance liquid chromatography with UV-Vis detection.
abstract: A high-performance liquid chromatography (HPLC) method for the determination of acetaldehyde in fuel ethanol was developed. Acetaldehyde was derivatized with 0.900 mL 2,4-dinitrophenylhydrazine (DNPHi) reagent and 50 microL phosphoric acid 1 mol L(-1) at a controlled room temperature of 15 degrees C for 20 min. The separation of acetaldehyde-DNPH (ADNPH) was carried out on a Shimadzu Shim-pack C18 column, using methanol/LiCl((aq)) 1.0 mM (80/20, v/v) as a mobile phase under isocratic elution and UV-Vis detection at 365 nm. The standard curve of ADNPH was linear in the range 3-300 mg L(-1) per injection (20 microL) and the limit of detection (LOD) for acetaldehyde was 2.03 microg L(-1), with a correlation coefficient greater than 0.999 and a precision (relative standard deviation, RSD) of 5.6% (n = 5). Recovery studies were performed by fortifying fuel samples with acetaldehyde at various concentrations and the results were in the range 98.7-102%, with a coefficient of variation (CV) from 0.2% to 7.2%. Several fuel samples collected from various gas stations were analyzed and the method was successfully applied to the analysis of acetaldehyde in fuel ethanol samples.
authors.affiliation: UNESP, Instituto de Química, Rua Prof. Francisco Degni s/n, Quitandinha, 14800-900 Araraquara, SP, Brazil.
authors.forename: Adelir Aparecida
authors.initials: AA
authors.lastname: Saczk
authors.forename: Leonardo Luiz
authors.initials: LL
authors.lastname: Okumura
authors.forename: Marcelo
authors.initials: M
authors.lastname: Firmino de Oliveira
authors.forename: Maria Valnice
authors.initials: MV
authors.lastname: Boldrin Zanoni
authors.forename: Nelson
authors.initials: N
authors.lastname: Ramos Stradiotto