## 3 Results and Discussion
### Method Validation
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Volatile Compounds** & \multicolumn{2}{c}{**Linear Range**} & \multicolumn{2}{c}{**LOD**} & \multicolumn{2}{c}{**LOQ**} & \multicolumn{2}{c}{**Intraday**} & \multicolumn{2}{c}{**Interday**} & \multicolumn{1}{c}{**Recovery**} \\  & \multicolumn{2}{c}{**(ug/L)**} & \multicolumn{2}{c}{**(ng/L)**} & \multicolumn{2}{c}{**(ng/L)**} & \multicolumn{2}{c}{**(\%)**} & \multicolumn{2}{c}{**(\%)**} & \multicolumn{2}{c}{**(\%)**} \\ \hline Benzaldehyde & 58.21-1862.72 & 0.999 & 58.56 & 195.20 & 4.99 & 6.75 & 99.25 \\
2-Octanone & 11.22–5743.20 & 0.9905 & 13.45 & 44.82 & 5.55 & 4.88 & 86.79 \\ Phenylacetaldehyde & 103.33–13,226.36 & 0.9986 & 1004.68 & 3348.92 & 0.77 & 7.57 & 98.87 \\ Propanal & 16.71–8555.70 & 0.9935 & 292.70 & 975.67 & 1.16 & 4.17 & 99.70 \\ Octanal & 1.76–900.13 & 0.9926 & 23.65 & 78.84 & 5.02 & 2.94 & 106.08 \\ Nonanal & 5.60–2868.71 & 0.9943 & 6.83 & 22.77 & 5.72 & 3.64 & 99.36 \\
1-Octen-3-one & 0.39–199.77 & 0.9982 & 38.02 & 126.72 & 1.89 & 2.82 & 101.62 \\ (E, Z)-2,6-Nonadien & 0.24–124.82 & 0.9981 & 33.64 & 112.13 & 1.54 & 3.89 & 105.50 \\
3-Methylbutanal & 833.01–1106,624.86 & 0.9935 & 177.73 & 592.42 & 7.44 & 8.91 & 110.06 \\ (E, E)-2,4-Hexadienal & 3.90–499.25 & 0.9945 & 50.40 & 167.99 & 7.62 & 0.51 & 105.77 \\ (E, E)-2,4-Decadien & 0.70–179.78 & 0.9919 & 15.13 & 50.44 & 0.60 & 0.40 & 90.92 \\ (E, E)-2,4-Nonadienal & 0.39–50.04 & 0.9924 & 6.14 & 20.46 & 0.82 & 5.47 & 89.37 \\ Hexanal & 34.35–8793.90 & 0.9993 & 558.22 & 1860.74 & 1.39 & 2.02 & 93.31 \\
1,1,3-Triethoxypropane & 6.88–3520.47 & 0.9988 & 6017.76 & 20,059.20 & 0.44 & 6.12 & 97.18 \\
2-Nonanone & 3.45–1765.25 & 0.994 & 1.13 & 3.77 & 0.71 & 7.40 & 91.82 \\ Acetophenone & 3.27–417.96 & 0.9924 & 8.77 & 29.22 & 1.01 & 4.16 & 92.81 \\
**Furans** & & & & & & & \\
5-Methyl-2-acetylfuran & 35.48–4541.41 & 0.9993 & 46.21 & 154.03 & 3.79 & 9.50 & 99.75 \\ Furfuryl alcohol & 11.52–5900.35 & 0.9897 & 730.23 & 2434.10 & 4.37 & 9.24 & 102.21 \\ Furfural & 200.81–51,406.86 & 0.9958 & 153.63 & 512.11 & 7.77 & 0.95 & 101.29 \\
2-Acetylfuran & 6.35–3249.79 & 0.9961 & 49.68 & 165.59 & 0.60 & 4.28 & 93.58 \\ Ethyl 2-fluoroate & 18.26–584.20 & 0.999 & 57.53 & 191.76 & 1.89 & 9.62 & 97.75 \\
5-Methylly furfural & 9.77–5003.88 & 0.9949 & 35.51 & 118.36 & 1.67 & 9.03 & 92.99 \\
**Pyrazi** & & & & & & & \\
2,6-Dimethylpyrazine & 42.63–21,824.65 & 0.9962 & 282.14 & 940.48 & 6.39 & 7.40 & 99.70 \\
2-Methylpyrazine & 30.53–3907.93 & 0.9991 & 1234.73 & 4115.76 & 2.05 & 8.89 & 101.51 \\
2,3,5,6-Tetramethylpyrazine & 13.79–7058.28 & 0.9934 & 222.93 & 743.08 & 4.80 & 4.82 & 102.52 \\
2-Methyl-6-ethylpyrazine & 7.82–4001.93 & 0.9975 & 78.95 & 263.18 & 3.83 & 9.93 & 97.75 \\
2,3,5-Trimethylpyrazine & 10.24–5244.50 & 0.995 & 126.96 & 423.18 & 5.84 & 8.64 & 105.46 \\
2,3-Diethylpyrazine & 1.97–503.46 & 0.9881 & 244.59 & 815.29 & 5.86 & 4.72 & 96.43 \\
2,3-Diethyl-5-methylpyrazine & 0.39–200.30 & 0.9986 & 90.86 & 302.88 & 4.26 & 8.88 & 95.33 \\
2,3-Dimethylpyrazine & 1.54–787.52 & 0.9898 & 654.62 & 2182.06 & 6.26 & 6.57 & 90.94 \\
**Sulfur compounds** & & & & & & \\ Methional & 54.87–28,092.79 & 0.9989 & 41.47 & 136.85 & 6.04 & 9.62 & 98.64 \\ Methyl1 furfuryl disulfide & 5.30–403.27 & 0.992 & 1.75 & 5.83 & 4.37 & 6.35 & 95.38 \\ Dimethyl disulfide & 9.71–621.28 & 0.9964 & 571.31 & 1904.37 & 6.48 & 6.10 & 100.51 \\ Furfuryl mercaptan & 2.31–1182.16 & 0.9917 & 212.26 & 707.52 & 4.27 & 2.03 & 109.64 \\ Ethyl 3-methylhypropionate & 1.32–67.40 & 0.9952 & 165.67 & 552.24 & 4.12 & 1.55 & 101.58 \\ Methylthiobutyrate & 0.78–399.74 & 0.9981 & 148.20 & 494.00 & 2.57 & 7.30 & 109.68 \\ Thiazole & 1.58–810.31 & 0.9987 & 25.02 & 82.57 & 9.02 & 0.14 & 100.09 \\ Dimethyl trisulfide & 24.85–795.25 & 0.993 & 1.36 & 4.49 & 1.59 & 4.92 & 94.21 \\ Methionol & 50.58–12,949.55 & 0.9962 & 14.44 & 47.65 & 5.62 & 6.97 & 99.75 \\ Methyl 2-methyl-3-furyl disulfide & 0.20–50.10 & 0.9911 & 26.08 & 86.95 & 4.07 & 9.83 & 96.42 \\ Methanethionl & 3.91–4000.00 & 0.9979 & 34.38 & 114.59 & 8.89 & 2.92 & 101.94 \\
**Phenols** & & & & & & \\
4-Methylphenol & 25.41–3252.20 & 0.9925 & 48.96 & 163.19 & 8.80 & 6.60 & 107.67 \\
3-Methylphenol & 0.78–199.90 & 0.9945 & 26.24 & 87.45 & 9.10 & 7.38 & 90.94 \\ Phenol & 5.08–649.68 & 0.9916 & 16.48 & 54.93 & 2.08 & 2.56 & 111.94 \\
4-Ethylphenol & 3.72–475.86 &