## 2 Results and Discussion
### Hydrolates  
According to [PERSON] and [PERSON] [10], about 30% of the EO constituents remain in the hydrolate during hydro-distillation, which represents a major product loss. The main volatile components in hydrolates are monoterepene alcohols, aldehydes, ketones, and sesquiterpene alcohols, while lipophilic compounds such as non-oxygenated monoterpens are usually absent or present in negligible amounts due to their low water solubility [18]. According to [PERSON] et al. [18], the similarity between the composition of EOs and their corresponding hydrolates depends mainly on the relation of hydrocarbons and oxygenated compounds in an EO. When oxygenated compounds dominate in EOs, there is a high similarity between the composition of EOs and hydrolates, while the chemistry of hydrolates differs significantly from the composition of EOs in the case of hydrocarbons. The results of the chemical composition of sea fennel hydrolates extracted by headspace-solid phase microextraction (HS-SPME) and detected by GC-MS are shown in Table 2 and in Figure 2.  
Figure 2: GC-MS total ion chromatogram of sea fennel hydrolates obtained hydro-distillation (**a**) and microwave-assisted hydro-distillation (**b**). Peak assignment is given in Table 2.  
\begin{table}
\begin{tabular}{c l c c c c c c} \hline \hline
**No. ** & **Component** & **Rt** & **LRI** & **Literature LRI** & **HD (\%)** & **MHD (\%)** & **Mode of Identification** \\ \hline
1. & benzaldehyde & 10.747 & 950 & 952 & \(0.46\pm 0.11\) & 0.70 \(\pm\) 0.02 & GC, MS \\
2. & (_E_,_E_)-heptudenial & 13.695 & 1005 & 1005 & 0.91 \(\pm\) 0.04 & tr & GC, MS \\
3. & limone & 14.552 & 1021 & 1024 & \(1.16\pm 0.11\) & 0.61 \(\pm\) 0.02 & GC, MS \\
4. & benzacetaldehyde & 15.402 & 1037 & 1036 & 5.34 \(\pm\) 0.01 & 1.15 \(\pm\) 0.04 & GC, MS \\
5. & \(\gamma\)-terpinene & 16.259 & 1054 & 1054 & tr & tr & GC, MS \\
6. & (_Z_)-sabinene hydrate & 16.659 & 1061 & 1065 & 1.54 \(\pm\) 0.26 & 3.95 \(\pm\) 0.04 & GC, MS \\
7. & (_E_)-sabinene hydrate & 18.294 & 1093 & 1098 & 2.37 \(\pm\) 0.36 & 4.72 \(\pm\) 0.08 & GC, MS \\
8. & linalo & 18.536 & 1097 & 1095 & 1.29 \(\pm\) 0.04 & 0.60 \(\pm\) 0.01 & GC, MS \\
9. & 6-methyl-3,5-heptuden-2-one & 18.750 & 1101 & 1107 & 0.45 \(\pm\) 0.05 & tr & GC, MS \\
10. & (_E_)-\(p\)-mentha-2,8-dienol & 19.488 & 1116 & 1118 & 2.40 \(\pm\) 0.03 & 4.34 \(\pm\) 0.83 & GC, MS \\
11. & (_Z_)-\(p\)-mentha-2,8-dienol & 20.216 & 1131 & 1133 & 1.49 \(\pm\) 0.17 & 2.50 \(\pm\) 0.13 & GC, MS \\
12. & (_E_)-limone oxide & 20.359 & 1134 & 1137 & nd & 1.84 \(\pm\) 0.37 & GC, MS \\
13. & (_E_)-\(p\)-mentha-2-en-1-ol & 20.421 & 1135 & 1136 & 1.38 \(\pm\) 0.21 & 1.18 \(\pm\) 0.07 & GC, MS \\
14. & terpinen-4-ol & 22.446 & 1176 & 1174 & 13.86 \(\pm\) 0.56 & 17.45 \(\pm\) 0.87 & GC, MS \\
15. & 3-methylacetophenone & 22.649 & 1180 & 1179 & 1.13 \(\pm\) 0.02 & 0.74 \(\pm\) 0.20 & GC, MS \\
16. & \(p\)-cymen-8-ol & 22.794 & 1183 & 1179 & 0.82 \(\pm\) 0.05 & tr & GC, MS \\
17. & isocarveol & 22.896 & 1185 & 1187 & 1.23 \(\pm\) 0.06 & 4.17 \(\pm\) 0.32 & GC, MS \\
18. & \(a\)-terpineol & 23.032 & 1188 & 1186 & 2.92 \(\pm\) 0.02 & 3.85 \(\pm\) 0.03 & GC, MS \\
19. & isocarveomenthone & 23.078 & 1189 & 1194 & 0.87 \(\pm\) 0.01 & Tr & GC, MS \\
20. & (_Z_)-carvomethone & 23.221 & 1192 & 1194 & nd & 2.52 \(\pm\) 0.01 & GC, MS \\
21. & (_Z_)-dihydrocarvone & 23.307 & 1194 & - & nd & 1.12 \(\pm\) 0.12 & GC, MS \\
22. & (_E_)-carvomethone & 23.482 & 1197 & - & 1.53 \(\pm\) 0.10 & 1.63 \(\pm\) 0.40 & GC, MS \\
23. & (_E_)-piperitol & 23.826 & 1204 & 1207 & 0.35 \(\pm\) 0.02 & 0.45 \(\pm\) 0.03 & GC, MS \\
24. & (_E_)-carveol & 24.438 & 1218 & 1215 & 4.92 \(\pm\) 0.29 & 5.70 \(\pm\) 0.35 & GC, MS \\
25. & neoiso dihydro carveol & 24.591 & 1221 & 1226 & 3.03 \(\pm\) 0.16 & 3.20 \(\pm\) 0.46 & GC, MS \\
26. & (_Z_)-carveol & 24.828 & 1226 & 1226 & 1.58 \(\pm\) 0.01 & 1.25 \(\pm\) 0.35 & GC, MS \\
27. & carvone & 25.520 & 1241 & 1239 & 1.10 \(\pm\) 0.03 & tr & GC, MS \\
28. & \(a\)-ionene & 25.848 & 1248 & - & 0.50 \(\pm\) 0.01 & nd & GC, MS \\
29.