## 3 Results
### Analysis of Wine Samples
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c} \hline \hline \# & **KT (min)** & **LRI\({}^{\textbf{A}}\)** & **Stationary Phase \({}^{\textbf{1-19}}\)** & **Compound** & **MW** & **\({}^{\textbf{B}}\) & **Foch** & **\({}^{\textbf{B}}\) & **St. Coix** & **\({}^{\textbf{B}}\) & **Frontenca** & **\({}^{\textbf{B}}\) & **Foch/Frontenca** & **\({}^{\textbf{C}}\) & **Vincent** & **\({}^{\textbf{D}}\) & **Frontenca** & **\({}^{\textbf{D}}\) & **Foch** \\ \hline
29 & 20.27 & 1788 & 2 & Phenethyl acetate & 164 & 0.95 & 1.56 & 1.26 & 1.41 & 0.95 & 1.47 & 1.2 \\  & & 1758 & 2 & & & & & & & & \\  & & 1233 & 8 & & & & & & & & \\ \hline
30 & 20.98 & 1903 & 4 & Benzoreethanol & 122 & 41.3 & 146 & 56 & 232 & 111 & 53.7 & 134 \\ \hline
31 & 23.06 & 2007 & 2 & Octanoic acid & 144 & 1.39 & 1.07 & 6.63 & 0.09 & 1.99 & 2.22 & 0.7 \\  & & 2007 & 2 & & & & & & & & \\  & & 2100 & 2 & & & & & & & & \\  & & 2013 & 2 & & & & & & & & \\  & & 2075 & 4 & & & & & & & & \\  & & 1185 & 6 & & & & & & & & \\  & & 1256 & 7 & & & & & & & & \\ \hline
32 & 23.36 & 1995 & 6 & Ethyl laurate & 228 & 3.3 & 2.63 & 6.73 & 1.62 & 1.28 & 8.24 & 2.72 \\ \hline
33 & 24.76 & & & 4-Ethylphenol & 122 & nd & 7.49 & 2.32 & nd & nd & 3.4 & 2.33 \\ \hline
34 & 24.81 & & & 8-Prattadecence & 226 & 1.06 & 7.49 & 2.31 & 2.53 & 2.33 & 3.4 & 2.32 \\ \hline
35 & 26.57 & & & Glycerol & 92 & nd & nd & 26.8 & nd & nd & nd \\ \hline
36 & 26.63 & 1793 & 6 & Ethyl myistate & 256 & 0.39 & 0.53 & 0.48 & 0.38 & 0.57 & 0.84 & 0.99 \\ \hline
37 & 29.63 & 1993 & 6 & Ethyl palmitate & 284 & 2.35 & 2.1 & 5.75 & 1.92 & 2.81 & 4.12 & 5.14 \\  & 1985 & 7 & & & & & & & & & \\ \hline \hline \end{tabular} Note. \# is the chromatographic peak number. RT is the retention time in minutes. A is the GC capillary column linear retention index from the LRI & Odor Database [16]. GC stationary phases are: \(-\)CL-Wax, \(-\)CW20M, \(3-\)DB-170M, \(4-\)DB-Wax, \(5-\)DB1, \(6-\)DB5, \(7-\)HF-1, \(8-\)OV-101, \(9-\)SP-Max, \(10-\)SP-1. MW is the molecular weight. B, C, and D stand for the three different Iowa varieties. RS internal standard.  
\end{table} 
Table 2: _Cont._Simultaneous olfactory, when used with GC-MS, can verify compounds by aroma character. An example of this is highlighted in Figure 8. The chromatographic peak at 19 min was not identified by mass spectral comparison, but it was recorded with an aroma character of burnt food (aromagram peak number 27). An open source aroma database search narrows the possible identification of this compound from hundreds to six: octanol, indole, 3-methyl-1-butanol, ethyldimethylpyrazine, dimethyl sulfone, or furfuryl alcohol [17]. The use of olfactory, by means of the human nose as a detector, is a very valuable tool for the identification of unknown compounds. The total aroma values, calculated as the sum of the area under the aromagram peaks, are compared in Figure 9 and no significant differences are exhibited between the seven Iowa red wines. Figure 8: Overlay of total ion chromatogram and aromagram of an Iowa Maréchal Foch wine using the optimized method. Intense aromas (observed as increased peak height, black signal) and responsible chemical compounds (TIC, red signal) were aromagram peak: (#6) sweet, fruity—ethyl isobutyrate (4.71 min); (#11) fruity—ethyl isovalerate (7.21 min); (#24) rancid, sweaty, body odor, burnt—isovaleric acid (16.83 min) (#27) burnt, burnt food—unknown compound (19 min); (#31) sweet, fruity, wines—ethyl laurate (23.26 min). Conditions: 2 min pre-sampling desorption of 50/30 μm DVB/CAR/PDMS SPME fiber; 4 mL wine sample in a 10 mL threaded glass amber vial with PTFE/silicone septa; 10 min incubation at 50 \({}^{\circ}\)C; 10 min extraction time at 50 \({}^{\circ}\)C; agitation speed 500 rpm; 2 min desorption time into GC inlet.