## 2 Results and Discussion
### Headspace Composition of the Volatile Organic Compounds Isolated by HS-SPME--Plant and Hydrosol  
For the first time, both fresh (HS-Fr) and air-dried (HS-Dr) plants as well as hydrosol obtained from hydrodistillation (HS-HY) of the air-dried plants were isolated by HS-SPME. To obtain more accurate information on the headspace composition, two fibres with different polarity were used: divinylbenzene/carboxylate/polydimethylsiloxane (DVB/CAR/PDMS, f1) and polydimethylsiloxane/divinylbenzene (PDMS/DVB, f2). In HS-Fr, 99.75% (f1) and 99.82% (f2), in Hs-Dr 99.63% (f1) and 99.66% (f2), and in HS-HY 99.48% (f1) and 99.38% (f2) of the total VOCs detected were identified. The identified compounds were classified into three structural groups: benzene derivatives, terpen, and  
Figure 1: Volatile organic compounds of air-dried _P. ramossissima_ isolated by hydrodistillation, analyzed by gas chromatography-mass spectrometry and sorted by structural groups. EO—essential oil; HY—hydrosol. Figure 2: The most abundant compounds in air-dried _P. ramossissima_ samples obtained by hydrodistillation and analyzed by gas chromatography–mass spectrometry. EO—essential oil; HY—hydrosol. others (Figure 3). The benzene derivative group was the dominant group extracted from both fibres in all samples: HS-Fr (70.66%, f1; 73.13%, f2); HS-Dr (67.17%, f1; 77.31%, f2), and HS-HY (90.64%, f1; 91.31%, f2) with myristicin as the most abundant component of all (Table 2). The second most abundant group of compounds, terpen, differed from fibre to fibre. When analyzed with DVB/CAR/PDMS (f1), the fibres HS-Fr (26.08%) and HS-Dr (27.77%) had a similar percentage of identified terpen, while analysis of the dry plant material with PDMS/DVB (f2) noted the decreased percentage of terpen (25.17%, HS-Fr; 19.81%, HS-Dr). Although it could be concluded that some of the terpen were lost by drying, analysis with f1 fibre showed a similar percentage of identified terpen in fresh and dry material. This comprehensive analysis of fresh and dry plant material using two fibres for the first time thus gives a complete insight into the composition of volatiles of this plant species. Monoterpenes are again prevalent, with (_E_)-\(\beta\)-ocimene, sabinene, \(\gamma\)-terpinene, and thymol methyl ether being the most abundant (Figure 4). The proportion of sesquiterpenes in the headspace of fresh and air-dry plants is greater than in hydrosol, with \(\beta\)-caryophyllene being the most abundant. Terpene alcohols were present in greater abundance in HS-HY than in HS-Fr and HS-Dr. Terpinen-4-ol was the one with the largest percentage (5.31%, f1; 4.72%, f2) (Figure 4). Among others, aliphatic compounds were the most abundant especially in the headspace of the air-dried plant. This could be the result of fatty acid degradation. The phytochemical composition of the fresh and dry material as well as the isolated extracts is important for further studies and possible applications of this plant in daily life. The analyses performed revealed a fairly constant composition of the volatile components, indicating that both fresh and dry plant material can be used. Figure 3: The volatile organic compounds of _P. ramossissima_ extracted by headspace solid-phase microextraction, analyzed by gas chromatography-mass spectrometry and sorted by structural groups. Extraction by divinylbenzene/carboxylate/polydimethylsiloxane fibre (f1): HS-Fr (f1)—fresh _P. ramossissima_; HS-Dr (f1)—air-dried _P. ramossissima_; HS-HY (f1)—hydrosol of air-dried _P. ramossissima_. Extraction by polydimethylsiloxane/divinylbenzene fibre (f2): HS-Fr (f2)—fresh _P. ramossissima_; HS-Dr (f2)—air-dried _P. ramossissima_; HS-HY (f2)—hydrosol of air-dried _P. ramossissima_. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**No.