## 2 Results
### Semi-Quantitative Analysis of Individual and Total MTs  
In the first sampling point (Figure 1), a similar trend was common for both sampling techniques. In particular, \(\alpha\)-pinene resulted as the most abundant compound sampled using both techniques, while \(\alpha\)-thujene was the second most abundant compound only in samples collected by the DBSS technique. All peak areas were higher in samples collected by DBSS compared to the static technique. A similar trend was also found in the second sampling point (Figure 2). The most abundant compounds were \(\alpha\)-pinene and \(\beta\)-pinene, followed by \(\alpha\)-thujene, car-3-ene, d-limonene and \(p\)-cymene. Similar to sampling point 1, the amounts of the single compounds collected by DBSS were higher compared to the static technique. \begin{table}
\begin{tabular}{c c c c c c} \hline
**n. Peak** & \begin{tabular}{c} **Compound** \\ **Identified** \\ \end{tabular} & **RT** & \multicolumn{3}{c}{**Presence**} \\ \hline  & & \begin{tabular}{c} (min) \\ (dynamic/static) \\ \end{tabular} & \begin{tabular}{c} SP 1 \\ (dynamic/static) \\ \end{tabular} & \
\begin{tabular}{c} SP 2 \\ (dynamic/static) \\ \end{tabular} &
\begin{tabular}{c} SP 3 \\ (dynamic/static) \\ \end{tabular} \\
1 & \(\alpha\)-pinene & \(10.07\pm 0.02\) & y/y & y/y & y/y \\
2 & \(\alpha\)-thujene & \(10.15\pm 0.02\) & y/y & y/y & y/y \\
3 & \(\alpha\)-exphene & \(11.35\pm 0.05\) & y/y & y/y & y/y \\
4 & \(\beta\)-pinene & \(12.61\pm 0.04\) & y/y & y/y & y/y \\
5 & \(\mathrm{sabinene}\) & \(12.76\pm 0.05\) & y/y & y/y & y/y \\
6 & \(\mathrm{car}\)-3-ene & \(12.97\pm 0.03\) & y/y & y/y & y/n \\
7 & \(\beta\)-phellandrene & \(13.10\pm 0.03\) & n/n & y/y & n/n \\
8 & \(\mathrm{myrcne}\) & \(14.12\pm 0.02\) & n/n & y/y & y/n \\
9 & \(\alpha\)-phellandrene & \(14.35\pm 0.02\) & n/n & y/y & n/n \\
10 & \(\alpha\)-terpinene & \(14.83\pm 0.04\) & n/n & y/y & y/n \\
11 & \(\mathrm{d}\)-limonene & \(15.39\pm 0.02\) & y/y & y/y & y/y \\
12 & \(\mathrm{1}\),\(\mathrm{s}\)-cine & \(15.68\pm 0.01\) & y/y & n/n & n/n \\
13 & \(\beta\)-cis-coimene & \(15.72\pm 0.02\) & n/n & y/y & y/y \\
14 & \(\beta\)-trans-ocimene & \(13.99\pm 0.02\) & n/n & n/n & y/n \\
15 & \(\gamma\)-terpinene & \(16.80\pm 0.01\) & n/n & y/y & y/n \\
16 & \(p\)-cymene & \(17.62\pm 0.02\) & y/y & y/y & y/y \\
17 & \(\mathrm{terpinolene}\) & \(17.95\pm 0.01\) & n/n & y/y & y/n \\ \hline \end{tabular}
\end{table} 
Table 1: A list of the identified compounds by comparison with the NIST 11 library. Their names and retention times (RT) are presented. The peak number (n. Peak) corresponds to the numbers reported in the chromatograms (Figure S1). It is also reported the presence (y: yes) or the absence (n: no) of each compound in each the different sampling points (SP 1, SP 2 or SP 3) and in the two sampling conditions (dynamic/static). Figure 1: Radar-plot showing the results of the semi-quantitative analysis of BVOCs at sampling point 1 (\(n=3\)) expressed as the peak area of each individual compound. The amounts of different compounds range between 0 and 350,000. Results of statistical analysis are reported in Table S1. In the case of sampling point 3, the amounts of BVOCs collected using the DBSS were much higher than those found using the static sampling technique (Figure 3). In addition, at this sampling point, the DBSS allowed collecting a wider range of MTs compared to the samples collected using the static technique (Table 1). Indeed, compounds, such as car-3-ene, myrcene, \(\alpha\)-terpinene, \(\beta\)-trans-ocimene, \(\gamma\)-terpinene and terpinolene, were detected only when using the DBSS. Finally, there is a slight difference in the trend of samples collected by DBSS and by static sampling. The samples collected by DBSS contained mainly \(\alpha\)-pinene and \(p\)-cymene, followed by \(\beta\)-pinene and d-limonene, whereas in samples collected by the static technique, \(\alpha\)-pinene and \(\beta\)-pinene were the most abundant compounds, followed by d-limonene and \(p\)-cymene (Figure 4).