## 2 Results and Discussion
### Headspace, Volatile, and Semi-Volatile Organic Compounds
& Nonadecane [8] & \multirow{2}{*}{\(1900\)} & \multirow{2}{*}{\(1900\)} & \multirow{2}{*}{\(1900\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{\(\pm\) 0.02  & - \\ \hline
55. & Dibutyl phthalate [5] & \multirow{2}{*}{\(1961\)} & \multirow{2}{*}{\(1960\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{\(\pm\) 1.13 [FOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] } \\ \hline
56. & Hexadecan-oic acid [5] & \multirow{2}{*}{\(1963\)} & \multirow{2}{*}{\(1960\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \(\pm\) 1.13 [FOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] \\ \hline
57. & Eicosane [5] & \multirow{2}{*}{\(2000\)} & \multirow{2}{*}{2000} & \multirow{2}{*}{-} & \(\pm\) 0.40 [FOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] & - & - & - & - & - \\ \hline
58. & Cyclocotcasulfur & \multirow{2}{*}{\(2009\)} & \multirow{2}{*}{\(2004\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \(\pm\) 0.21  & \\ \hline
59. & (Z)-Octadec-9-en-1-ol [8] & \multirow{2}{*}{\(2060\)} & \multirow{2}{*}{\(2060\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \(\pm\) 0.12 [FOOTNOTE:]Footnote : footnotemark: [ENDFOOTNOTE] \\ \hline
60. & Octadecan-1-ol [8] & \multirow{2}{*}{\(2084\)} & \multirow{2}{*}{\(2083\)} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \multirow{2}{*}{-} & \(\pm\) 0.12 [FOOTNOTE:]Footnote :oxygen species and, thus, may serve as an antioxidant system (e.g., for the reduction of oxidative stress), regulated in part by DMSP enzymatic cleavage [30]. DMPS has been found in green algae, and the spatial and temporal distribution of DMSP content in _C. fingile_ of the Atlantic coast of Nova Scotia was investigated [31]. Heptadecane was another abundant compound (4.82%; 32.51%) in HS-F, being more abundant when applying HS-SPME with PDMS/DVB fiber. Saturated and olefinic hydrocarbons were already determined in different species of benthic marine algae [32; 33]. Heptadecane dominated in red algae but was also abundant in _C. fragile_ (89%) after the extraction, chromatographic purification, and GC analysis (before and after hydrogenation) [32]. In general, aliphatic hydrocarbons result from highly endergenic metabolic processes of fatty acids decarboxylation [34]. The results of an incubation of stearic-18-14C acid showed an exclusive incorporation of radioactivity into heptadecane indicating direct decarboxylation of stearic acid [34]. Several low-molecular aliphatic aldehydes were present, such as nonanal (3.51%; 2.51%), octanal (0.81%; 0.10%), and decanal (1.01%; 0.42%). They could originate from \(\omega\)9 MUFAs and also from \(\omega\)6 PUFAs, such as linoleic acid [35]. Aliphatic lower alcohols oct-1-en-3-ol (1.12%; 9.71%) and octan-1-ol (0.62%; 0.20%) were also found. The biosynthetic pathways of vinylic alcohols in diatoms include the lyase activity and utilize water from the medium, presumably to assist the carbon-carbon bond cleavage and lipoxygenase catalyzes both the oxygenation of arachidonic acid and the lyase reaction leading to the formation of oct-1-en-3-ol [36]. Another abundant compounds in HS-F were aromatic compounds (benzaldehyde (5.21%; 4.73%) and benzyl alcohol (9.31%; 0.20%)) that are known to derive from phenylalanine by shortening of the carbon skeleton side chain by the C\({}_{2}\)-unit, which can potentially occur in the plant tissue _via_ either \(\beta\)-oxidative pathway or non-oxidatively [37]. The chemical composition of the headspace of dried _C. bursa_ (HS-D) was remarkably different. Namely, the major HS-F headspace compound, DMS, was present in the dried sample only as a minor constituent (3.72%; 3.10%) and its percentage fall of was ca. 15.3 and 11.7 times, respectively (Table 1).