# HS-SPME Combined with GC-MS/O to Analyze the Flavor of Strong Aroma Baijiu _Daqu_
## 3 Results
### Analysis of Daqu at Different Maturity Stages by HS-SPME Combined with GC-MS
**} & \multirow{2}{*}{**Compound**} & \multicolumn{2}{c}{**CAS**} & \multirow{2}{*}{**RI**} & \multirow{2}{*}{**Identification \({}^{\text{a}}\)**} & \multicolumn{6}{c}{**Area Percentage \% b**} \\ \cline{5-10}  & & & & & \multicolumn{2}{c}{**S-0D**} & \multicolumn{2}{c}{**S-4D**} & \multicolumn{2}{c}{**S-6D**} & \multicolumn{2}{c}{**S-20D**} & \multicolumn{2}{c}{**S-3M**} \\ \hline Esters & & & & & & & & & & \\
25 & Ethyl & & & & & & & & & \\
25 & 3-phenylproanoate & 2021-28-5 & 1884 & S,MS,RI & 0.125 & 0.103 & 0.082 & 0.033 & 0.113 & 0.052 \\  & & & & & & & & & \\
26 & & 140-26-1 & 1978 & S,MS & — & 0.025 & 0.021 & — & — & 0.015 \\
27 & Ethyl tetradeacanoate & 124-06-1 & 2022 & S,MS,RI & 0.182 & 2.003 & 2.891 & 2.712 & 3.127 & 0.100 \\
28 & Ethyl cinnamate & 103-36-6 & 2094 & S,MS,RI & — & — & — & — & 0.042 \\
29 & Ethyl pentadecanoate & 41114-00-5 & 2099 & S,MS,RI & — & 0.494 & 0.715 & 1.320 & 1.186 & 1.251 \\
30 & Methyl hexadecanoate & 112-39-0 & 2181 & MS & — & — & — & — & 0.118 \\
31 & Ethyl hexadecanoate & 628-97-7 & 2227 & S,MS,RI & 2.777 & 14.552 & 18.454 & 23.904 & 22.731 & 29.140 \\
32 & Ethyl 9-hexadecenoate & 54546-22-4 & 2259 & S,MS,RI & — & 1.298 & 1.589 & 0.882 & 1.226 & 0.997 \\
33 & Ethyl heptadecanoate & 14010-23-2 & 2350 & S,MS,RI & — & 0.056 & 0.067 & 0.114 & — & 0.117 \\
34 & Ethyl octadecanoate & 111-61-5 & 2483 & S,MS,RI & — & 0.318 & 0.364 & 0.602 & 0.564 & 0.648 \\
35 & Ethyl Oleate & 111-62-6 & 2475 & S,MS,RI & 0.457 & 2.843 & 3.961 & 6.784 & 6.399 & 7.778 \\ Methyl & & & & & & & & & \\
36 & octadecadienoate & 112-63-0 & 2588 & S,MS & 0.107 & 3.214 & 3.614 & 5.067 & 6.111 & 6.372 \\  & & & & & & & & & & \\  & & & & & & & & & & \\ Acids & & & & & & & & & & \\
37 & Acetic acid & 64-19-7 & 1458 & S,MS,RI & 0.756 & 0.487 & 0.562 & 0.674 & 0.851 & 0.729 \\
38 & 2-Methylpropionic & 79-31-2 & 1569 & MS,RI & — & 0.645 & 0.214 & 0.077 & 0.077 & 0.085 \\
39 & 3-Methyllbutanoic acid & 503-74-2 & 1672 & MS,RI & 0.251 & 9.765 & 3.172 & 1.224 & 1.596 & 1.514 \\
40 & Hexanoic acid & 142-62-1 & 1846 & S,MS,RI & 1.253 & 0.165 & 0.037 & 0.288 & 0.185 & 0.336 \\
41 & Heptanoic acid & 111-14-8 & 1940 & MS,RI & 0.101 & 0.024 & 0.036 & — & — & — \\
42 & Octanoic acid & 124-07-2 & 2031 & S,MS,RI & 0.241 & — & — & — & 0.081 & 0.053 \\
43 & Decanoic acid & 334-48-5 & 2247 & MS,RI & 0.357 & — & — & — & — & — \\  & Subtotal & & & & & 2.959 & 11.086 & 4.021 & 2.263 & 2.789 & 2.717 \\ Alcohols & & & & & & & & & & \\
44 & 3-Methyl-1-butanol & 123-51-3 & 1202 & MS,RI & 0.373 & 4.540 & 4.454 & 2.077 & 0.514 & 4.323 \\
45 & 1-Pentanol & 71-41-0 & 1246 & MS & 0.827 & — & — & — & — & 0.873 \\
46 & 3-Methyl-2-buten-1-ol & 556-82-1 & 1321 & S,MS,RI & — & — & — & 0.089 & 0.020 & 0.342 \\
47 & 3-Octanol & 589-98-10 & 1391 & MS,RI & 0.328 & — & — & — & 0.415 & — \\
48 & 1-Octen-3-ol & 3391-86-4 & 1448 & S,MS,RI & 0.854 & 0.484 & 0.826 & 0.271 & 0.237 & 0.311 \\
49 & 1-Heptanol & 111-70-6 & 1452 & S,MS,RI & 1.342 & 0.055 & 0.126 & 0.671 & 0.497 & 0.151 \\
50 & 6-Methyl-5-hepten-2- & 1569-60-4 & 1462 & MS,RI & 0.489 & — & — & — & — & — \\  & & & & & & & & & & \\
51 & 2-Ethylhexanol & 104-76-7 & 1488 & S,MS,RI & 0.874 & 0.040 & 0.057 & 0.545 & 0.193 & 0.413 \\
52 & 2-Nonanol & 628-99-9 & 1517 & S,MS,RI & — & 0.083 & 0.101 & 0.180 & 0.095 & 0.043 \\
53 & 1-Octanol & 111-87-5 & 1556 & S,MS,RI & 0.428 & 0.053 & 0.066 & 0.148 & 0.097 & 0.139 \\
54 & 2,3-Butanediod & 513-85-9 & 1577 & S,MS,RI & 1.364 & 0.056 & 0.083 & 0.646 & 0.403 & 0.699 \\
55 & (E)-2-Octenol & 18409-17-1 & 1616 & S,MS,RI & 0.224 & 0.081 & 0.112 & — & — & — \\
56 & 1-Nonanol & 143-08-8 & 1659 & S,MS,RI & 0.166 & 0.055 & 0.051 & 0.054 & 0.056 & 0.061 \\
57 & (Z)-3-Nonen-1-ol & 10340-23-5 & 1684 & MS,RI & 0.104 & — & — & — & — \\
58 & \(\alpha\)-Terpineol & 98-55-5 & 1699 & S,MS,RI & 0.747 & 0.038 & 0.039 & 0.042 & 0.281 & 0.038 \\
59 & Methiond & 50-10-2 & 1721 & S,MS,RI & — & 0.071 & 0.118 & 0.108 & 0.046 & 0.047 \\
60 & 2-Phenyl-2-propanol & 617-94-7 & 1762 & S,MS,RI & — & — & — & 0.117 & 0.037 & 0.097 \\
61 & 1-Phenylethanol & 98-85-1 & 1819 & S,MS,RI & — & — & — & 0.057 & 0.019 \\
62 & Benzyl alcohol & 100-51-6 & 1878 & S,MS,RI & 0.188 & 0.228 & 0.176 & 1.318 & 1.033 & 2.233 \\
63 & Phenylethyl Alcohol & 60-12-8 & 1907 & S,MS,RI & 3.652 & 14.526 & 11.272 & 7.081 & 14.432 & 11.298 \\
64  
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\begin{tabular}{c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**No.