# New Methods for the Comprehensive Analysis of Bioactive Compounds in _Camabis sativa_ L. (hemp)
## 2 Results and Discussion
### GC Methods for the Analysis of Volatile Compounds from Hemp  
Hemp volatile compounds extracted by HS-SPME were analysed by GC-FID and GC-MS and they were identified according to both their calculated linear retention index (_LRI_) and MS spectra, which were compared with available data in the literature and MS spectral libraries, respectively. As shown in Figure 12 and Table 4, the GC analysis allowed us to identify 44 compounds in hemp infloresences.  
In general, all the hemp samples analysed in this study displayed the same qualitative and semi-quantitative profile: monoterpenes were the most represented class of compounds among volatiles, ranging between 47% and 89% of the total peak area. Sample C5 was the only exception to this trend, as the total area of sesquiterpenes (52% of the total area) was found to be higher than that of monoterpenes.  
\(\beta\)-Myrcene, \(\alpha\)- and \(\beta\)-pinene, and limonene represented the most abundant compounds among monoterpenes. It is worthy of notice that the head space of sample C2 had a remarkably high relative content of \(\alpha\)-pinene, while samples C4 and C6 displayed a notably high relative amount of limonene.  
As to the sesquiterpenes, \(\beta\)-caryophyllene was the most abundant compound in all the samples analysed, followed by \(\alpha\)-humulene. Curiously, sample C5 was the one with the higher relative content of cyanophyllene oxide, followed by sample C2. It should be pointed out that samples C2 and C5 were the same in that had a cannabinoid profile opposite to that of fresh plant material, further suggesting their aging or non-optimal storage conditions.  
Nevertheless, the GC data of the hemp infloresences analysed in this work are in accordance with the available one previously described in the literature relating to hemp essential oil or volatile fraction [14; 15; 27; 28; 29].  
Figure 12: Representative GC-FID chromatogram obtained by using the HS-SPME method optimised for volatile compounds from hemp infloresences (sample C3). For peak numbering, see Table 4.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Feak Number**} & \multirow{2}{*}{**Compound**} & \multirow{2}{*}{**LRI Calc.**} & \multirow{2}{*}{**LRI Li.**\({}^{\epsilon}\)} & \multicolumn{6}{c}{**\% Relative Peak Area**} \\ \cline{6-9}  & & & **Cl** & **C2** & **C3** & **C4** & **CS** & **C6** \\ \hline
1 & a-Thüjeme & 932 & 911 & \(3.7\pm 1.1\) & \(1.4\pm 1.0\  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Feak Number** & **Compound** & **LRI Calc.** & **LRI Lit \({}^{\epsilon}\)** & \multicolumn{5}{c}{**\% Relative Peak Area**} \\ \cline{6-9}  & & & **C1** & **C2** & **C3** & **C4** & **CS** & **C6** \\ \hline
36 & Germacrene D & 1489 & 1480 & - & - & - & 0.1\({}^{\text{b}}\) & 0.5\({}^{\text{b}}\) & - \\
37 & \(\beta\)-Selinene & 1493 & 1485 & 0.3\({}^{\text{b}}\) & 0.6\({}^{\text{b}}\) & - & 0.2\({}^{\text{b}}\) & 0.5\({}^{\text{b}}\) & 0.1\({}^{\text{b}}\) \\
38 & Valenore & 1496 & 1496 & 0.5\({}^{\text{b}}\) & - & 0.1\({}^{\text{b}}\) & 0.1\({}^{\text{b}}\) & 1.4\({}^{\text{b}}\) & 0.3\({}^{\text{b}}\) \\
39 & \(\alpha\)-Selinene & 1505 & 1484 & 0.4\({}^{\text{b}}\) & 0.4\({}^{\text{b}}\) & 0.1\({}^{\text{b}}\) & 0.1\({}^{\text{b}}\) & 1.2\({}^{\text{b}}\) \\
40 & \(\gamma\)-Calcinene & 1515 & 1514 & 0.3\({}^{\text{b}}\) & - & - & 0.6\({}^{\text{b}}\) + 0.2\({}^{\text{b}}\) & 0.4\({}^{\text{b}}\) & - \\
41 & \(\delta\)-Calcinene & 1532 & 1530 & - & - & 0.1\({}^{\text{b}}\) & 0.4\({}^{\text{b}}\) & - \\
42 & \(\alpha\)-Calcourene & 1547 & 1542 & - & - & 0.6\({}^{\text{b}}\) + 0.1 & 0.2\({}^{\text{b}}\) & 0.2\({}^{\text{b}}\) \\
43 & Celina-3/(11)-diene & 1554 & 1550 & - & 0.6\({}^{\text{b}}\) & - & 0.3\({}^{\text{b}}\) & - \\