title: Comparison of electron and chemical ionization modes for the quantification of thiols and oxidative compounds in white wines by gas chromatography-tandem mass spectrometry.
abstract: A rapid, sensitive method for assaying volatile impact compounds in white wine was developed using gas chromatography-tandem mass spectrometry (GC-MS/MS) technology, with a triple quadrupole analyzer operating in chemical ionization and electron impact mode. This GC-MS/MS method made it possible to assay volatile thiols (3SH: 3-sulfanylhexanol, formerly 3MH; 3SHA: 3-sulfanylhexyl acetate, formerly 3MHA; 4MSP: 4-methyl-4-sulfanylpentan-2-one, formerly 4MMP; BM: benzenemethanethiol; E2SA: ethyl 2-sulfanylacetate; and 2FM: 2-furanmethanethiol) and odoriferous oxidation markers (Sotolon: 4,5-dimethyl-3-hydroxy-2(5)H-furanone, methional, and phenylacetaldehyde) simultaneously in dry white wines, comparing electron impact (EI) and chemical ionization (CI) modes. More molecular ions were produced by CI than protonated molecules, despite the greater fragmentation caused by EI. So, even using the best reactant gas giving the highest signal for thiols, EI was the best ionization mode, with the lowest detection limits. For all compounds of interest, the limits of quantification (LOQ) obtained were well below their detection thresholds (ranging from 0.5 to 8.5ng/L for volatile thiols and 65-260ng/L for oxidation markers). Recovery rates ranged from 86% to 111%, reproducibility (in terms of relative standard deviation; RSD) was below 18% in all cases, with correlation coefficients above 0.991 for all analytes. The method was successfully applied to the analysis of compounds of interest in Sauvignon Blanc wines from a single estate and ten different vintages.
authors.affiliation: INRA, ISVV, USC 1366 Œnologie, FR-33140 Villenave d'Ornon, France; Univ. de Bordeaux, ISVV, EA 4577 Œnologie, F-33140 Villenave d'Ornon, France. Electronic address: cecile.thibon@u-bordeaux.fr.
authors.forename: Cécile
authors.initials: C
authors.lastname: Thibon
authors.affiliation: INRA, ISVV, USC 1366 Œnologie, FR-33140 Villenave d'Ornon, France; Univ. de Bordeaux, ISVV, EA 4577 Œnologie, F-33140 Villenave d'Ornon, France; SEGUIN MOREAU France, Z.I. Merpins, BP 94, 16103 Cognac, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Pons
authors.affiliation: INRA, ISVV, USC 1366 Œnologie, FR-33140 Villenave d'Ornon, France; Univ. de Bordeaux, ISVV, EA 4577 Œnologie, F-33140 Villenave d'Ornon, France.
authors.forename: Nadia
authors.initials: N
authors.lastname: Mouakka
authors.affiliation: INRA, ISVV, USC 1366 Œnologie, FR-33140 Villenave d'Ornon, France; Univ. de Bordeaux, ISVV, EA 4577 Œnologie, F-33140 Villenave d'Ornon, France.
authors.forename: Pascaline
authors.initials: P
authors.lastname: Redon
authors.affiliation: University de Bordeaux, ISM, UMR CNRS 5255, FR-33405 Talence, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Méreau
authors.affiliation: INRA, ISVV, USC 1366 Œnologie, FR-33140 Villenave d'Ornon, France; Univ. de Bordeaux, ISVV, EA 4577 Œnologie, F-33140 Villenave d'Ornon, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Darriet
mesh_terms: D000079:Acetaldehyde / Q000031:analogs & derivatives* / Q000032:analysis; D000447:Aldehydes / Q000032:analysis*; D005663:Furans / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D015203:Reproducibility of Results; D013438:Sulfhydryl Compounds / Q000032:analysis*; D053719:Tandem Mass Spectrometry; D014920:Wine / Q000032:analysis*
chemical_list: D000447:Aldehydes; D005663:Furans; D013438:Sulfhydryl Compounds; C008390:methional; C054511:4,5-dimethyl-3-hydroxy-2(5H)-furanone; D000079:Acetaldehyde; C013192:phenylacetaldehyde
keywords: Aldehyde; Chemical ionization; GC–MS/MS; Off flavor; Volatile thiols; White wine