title: Analysis of aldehydes in beer by gas-diffusion microextraction: characterization by high-performance liquid chromatography-diode-array detection-atmospheric pressure chemical ionization-mass spectrometry.
abstract: In this work, a recently developed extraction technique for sample preparation aiming the analysis of volatile and semi-volatile compounds named gas-diffusion microextraction (GDME) is applied in the chromatographic analysis of aldehydes in beer. Aldehydes-namely acetaldehyde (AA), methylpropanal (MA) and furfural (FA)-were simultaneously extracted and derivatized with 2,4-dinitrophenylhydrazine (DNPH), then the derivatives were separated and analyzed by high-performance liquid chromatography with spectrophotometric detection (HPLC-UV). The identity of the eluted compounds was confirmed by high-performance liquid chromatography-atmospheric pressure chemical ionization-mass-spectrometry detection in the negative ion mode (HPLC-APCI-MS). The developed methodology showed good repeatability (ca. 5%) and linearity as well as good limits of detection (AA-12.3, FA-1.5 and MA 5.4microgL(-1)) and quantification (AA-41, FA-4.9 and MA 18microgL(-1)); it also appears to be competitive in terms of speed and cost of analysis.
authors.affiliation: REQUIMTE-Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Rua do Campo Alegre, no. 687, 4169-007 Porto, Portugal. luis.goncalves@fc.up.pt
authors.forename: Luís Moreira
authors.initials: LM
authors.lastname: Gonçalves
authors.forename: Paulo Jorge
authors.initials: PJ
authors.lastname: Magalhães
authors.forename: Inês Maria
authors.initials: IM
authors.lastname: Valente
authors.forename: João Grosso
authors.initials: JG
authors.lastname: Pacheco
authors.forename: Pavel
authors.initials: P
authors.lastname: Dostálek
authors.forename: David
authors.initials: D
authors.lastname: Sýkora
authors.forename: José António
authors.initials: JA
authors.lastname: Rodrigues
authors.forename: Aquiles Araújo
authors.initials: AA
authors.lastname: Barros
mesh_terms: D000079:Acetaldehyde / Q000032:analysis / Q000737:chemistry; D000447:Aldehydes / Q000032:analysis* / Q000737:chemistry; D001515:Beer / Q000032:analysis*; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005662:Furaldehyde / Q000032:analysis / Q000737:chemistry; D016014:Linear Models; D013058:Mass Spectrometry / Q000379:methods*; D012680:Sensitivity and Specificity
chemical_list: D000447:Aldehydes; C017439:isobutyraldehyde; D005662:Furaldehyde; D000079:Acetaldehyde