Journal of Chemistry

Research Article

Comparison of an Electronic Nose Based on Ultrafast Gas Chromatography, Comprehensive Two-Dimensional Gas Chromatography, and Sensory Evaluation for an Analysis of Type of Whisky

Table 1

Selected compounds identified in a volatile fraction of whisky used as input data in chemometric analysis.
NameFragment ionsIrish whisky
1/2/3/4		Scotch whisky
1/2/3/4/5/6		Bourbon
1/2/3/4
1,1-Diethoxypropanal47, 75, 103+−−−−−−+−+++++
2-Methyl-1-butanol57, 41, 70++++++++++++++
3-Methyl-1-butanol55, 70, 42++++++++++++++
3-Methyl-1-butanol acetate43, 70, 55++++++++++++++
1-Decanol56, 70, 83++++++++++++++
1-Dodecanol55, 69, 83++++++++++++++
1-Heptanol41, 56, 70−−−−−−−−−−−++−
1-Hexanol56, 43, 69−−−+−+−−−−++++
2-Ethyl-1-hexanol57, 70, 83−−−−+−−+−−−+++
1-Nonanol56, 41, 70−−−+−−−−−−++++
1-Nonene41, 56, 69−−−−−++−−−++++
1-Octanol56, 41, 70,−−−−−−−−−−++++
2-Butyl-1-octanol57, 43, 69++++++++++++++
1-Octene43, 55, 70−−−−−+−−−−++++
1-Pentanol42, 55, 70−−−+−−−−−−++++
2-Methyl-1-propanol43, 74, 55++++++++++++++
1-Tetradecyl acetate43, 55, 69−+++−+−−−+−−−−
2-Dodecanol45, 55, 69−−−−−−−−−−+−+−
2-Furancarboxaldehyde96, 67, 51−−−+−++−−−+−++
2-Heptanone43, 58, 71−−−+−+−−+−−+−+
2-Nonanone43, 58, 71+−−+++−+−+++++
2-Octanone43, 58, 71−−−−+++−−−++++
2-Pentadecanone43, 58, 71−−++−++−−−−−−−
2-Undecanol45, 41, 55+−−+−−−++−−−−−
2-Undecanone43, 58, 71++++++++++++++
3-Methylbutyl dodecanoate70, 43, 55−++−++−+−−+−+−
3-Nonenoic acid, ethyl ester69, 55, 41+++−++++++++++
3,7,11-Trimethyl-6,10-dodecadien-1-ol69, 81, 123+−−++++−−−−−−−
Acetaldehyde44++++++++++++++
Acetic acid, 2-methylpropyl ester43, 56, 73++−++++−++++++
Acetic acid, 2-phenylethyl ester104, 43, 91++++++++++++++
Acetic acid, heptyl ester43, 56, 70+++++++−++++++
Acetic acid, hexyl ester43, 56, 61++++++++++++++
Acetic acid, nonyl ester43, 56, 70+++++−+−+++−++
α-Farnesene93, 107, 79−−−−−+++−+−−−−
α-Ionone121, 93, 43−−−−−−−−−−−++−
α-Muurolene105, 91, 161+−−+−−+−−+−++−
α-Pinene93, 77, 39++++++++++++++
Benzaldehyde77, 105, 51+−+++++++++−++
1,1-Dimethylpropylbenzene119, 91, 148−−−−−++−−−++−−
1-Ethylnonylbenzene91, 119, 41+−−−−+−++−−−−−
1-Methyldecylbenzene105, 91, 79+−+−−+−++−−−−−
1-Methylethylbenzene105, 120, 77+−−++++−+−++++
1-Pentylheptylbenzene91, 105, 119−−−−−+−++−−−−−
1-Propyloctylbenzene91, 133, 105−−−−−+−++−−−−−
Benzene, 1-(1,5-Dimethyl-4-hexenyl)-4-methylbenzene132, 119, 202+++−++−−−+−+++
1,2,3,4-Tetramethylbenzene119, 134, 91+++−+−+−−+−−−−
1-Ethyl-2,4-dimethylbenzene119, 134, 91−+−−−−+−+−++−−
1-Ethyl-2-methylbenzene105, 120, 77−++−−−+−++++++
1-Ethyl-4-methylbenzene105, 120, 77−+−−−+−+−+−+−+
1-Methyl-2-propylbenzene105, 134, 77−−−−−−+−−−++−−
1-Methyl-3-(1-methylethyl)benzene119, 91, 134−−++++++−+++−−
1-Methyl-4-(1-methylethenyl)benzene117, 132, 91−−−−−++−−+++++
Ethylbenzene91, 106, 51+++++++−++++++
Hexylbenzene91, 162, 65−−−−−+−−−−+−+−
Methylbenzene91, 65, 39−−−−−+++++−−−+
Pentylbenzene91, 148, 65+−−−−++−−−++++
Propylbenzene91, 120, 65−−−−−++−−−++++
Benzeneacetic acid, ethyl ester91, 65, 164+++−++++++++++
Benzofuran118, 89, 63−−−−+++−−−−−−−
Benzoic acid, ethyl ester105, 77, 122++++++++++++++
Biphenyl154, 76, 65++++−+++++−−−−
1,1-Diethoxy-3-methyl-butane103, 47, 71−−−−+++−−−+−−−
Butanedioic acid, diethyl ester101, 129, 55++−+−+−+++++++
2-Methylbutanoic acid, ethyl ester57, 102, 41−−+−+++−−−++++
3-Methylbutanoic acid, 3-methylbutyl ester85, 70, 57+−+−−−−−−−−−−+
Butanoic acid, 3-methylbutyl ester43, 71, 55−++−−−+−−−+−−+
Butanoic acid, ethyl ester71, 43, 88++++++++++++++
Camphene93, 121, 41−−+−−−−+−+++++
-Terpinene93, 121, 136−−−−++++++++−+
Decanal41, 57, 82++++++++++++++
Decanoic acid, ethyl ester88, 101, 43++++++++++++++
Decanoic acid, methyl ester74, 87, 143+++++++++++++−
Dodecane43, 57, 71−−++++++++++++
Dodecanoic acid, ethyl ester88, 101, 73++++++++++++++
Dodecanoic acid, methyl ester74, 87, 55+++++++−++++++
1,1-Diethoxy-ethane (CAS)45, 73, 103+−−+++++++++++
1-(2-Furanyl)-ethanone95, 110, 43−−−−++−−−+++−−
Ethyl 9-hexadecenoate55, 69, 88+−−−−+++++−−−−
Ethyl acetate43, 61, 70++−+++++++++−+
Ethyl tiglate55, 83, 113−−−−+++−−−++++
2,3-Dihydrofuran41, 70++−−++++++−−−+
Heptadecane57, 43, 71−−+−−+−+++++−+
Heptanoic acid, ethyl ester88, 113, 43++++++++++++++
Hexadecane43, 57, 71−−−−−+++++++−−
Hexadecanoic acid, ethyl ester88, 101, 43++−+++++++++++
Hexadecanoic acid, methyl ester74, 87, 43−+−−−−++−−+−+−
Hexanal44, 56, 72−−−−+++−−−++++
Hexanoic acid, ethyl ester88, 99, 70++++++++++++++
Hexyl octanoate43, 57, 145−−−−−−−−−−+++−
Isoamyl hexanoate43, 70, 99+++++++−++−−−+
Isobutyl caprate56, 41, 155++++++++−+++++
Isobutyl caprylate57, 127, 41+++++++−++++++
Isobutyl laurate56, 41, 183+−−−+++−++++−−
Isopentyl hexanoate70, 43, 99−−−−−−−−−−++−−
Methyl laurate91, 106, 77−+−−−+++++−+++
Nerolidol69, 41, 81−−−+++++++−−−+
Nonadecanoic acid, ethyl ester88, 101, 43−++−−−−−−−−−+−
Nonanal57, 70, 82−−−+−−−++−++++
Nonanoic acid, ethyl ester88, 101, 73++++++++++++++
Octadecanal43, 57, 82+−−−−+−−−−−+++
Octanoic acid, ethyl ester88, 57, 101++++++++++++++
Octanoic acid, methyl ester74, 87, 55+−++−+−−−−+−++
Oxalic acid, nonyl 2-phenylethyl ester104, 43, 55−++−−+−+++−−−−
Pentadecane57, 71, 85++++++++++++++
Pentadecanoic acid, ethyl ester88, 101, 70++++++++++++++
3-Methylpentanoic acid, ethyl ester88, 101, 43−+−+−−−−−−++++
Pentanoic acid, ethyl ester88, 57, 41−−−−+++−++++++
Phenylethyl alcohol91, 122, 65−−−−+++++−++++
2-Methylpropanal43, 72, 57−−+−+−+−−+−−−+
1,1-Diethoxy-2-methylpropane47, 103, 73−−−−+++−−−+−−+
2-Methylpropanoic acid, ethyl ester43, 71, 88−−+++++−−+++++
Propyl dodecanoate61, 43, 55+++++−+−++−−−+
Propyl hexanoate43, 99, 117−−−−−++−−−++−+
Styrene104, 78, 51−−−−+++−++++++
Tetradecane43, 57, 71++++++++++++++
Tetradecanoic acid, ethyl ester88, 101, 55++++++++++++++
Undecanal41, 57, 82++++++++++−+++
Undecanoic acid, ethyl ester88, 101, 73+++++++−+−++++
“+” means that the compound was considered to be identified if its spectra were at least 85% similar to the spectra included in NIST library and if the signal-to-noise (s/n) ratio was higher than 100
“−” means that the compound did not fulfill the above-mentioned requirements.