## 3 Results and Discussion
### Investigating the Modulation of Skin Volatile Profiles after Fragrance Application
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Compound** & **CAS** & **F1** & **F2** & **F3** & **F4** & **M1** & **M2** & **M3** & **M4** \\ \hline Hexanal & 66-25-1 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Benzaldehyde & 100-52-7 & \(\times\) & \(\times\) & & \(\times\) & \(\times\) & & \(\times\) & \\
6-Methyl-5-hepten-2-one & 110-93-0 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\
2,6-Dimethyl-2,6-octadiene & 2792-39-4 & \(\times\) & & & \(\times\) & & \(\times\) & \(\times\) & \\ Octanal & 124-13-0 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Nonanal & 124-19-6 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Octanoic acid & 124-07-2 & & & & & & & & \(\times\) \\ Decanal & 112-31-2 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\
2-Decenal & 2497-25-8 & \(\times\) & & & & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Nonanoic acid & 112-05-0 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Undecanal & 112-44-7 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\
2-Undecenal & 2463-77-6 & \(\times\) & & & & \(\times\) & & & \(\times\) \\ _n_-Decanoic acid & 334-48-5 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Geranyl acetone & 689-67-8 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\
1-Dodecanol & 1125-83 & \(\times\) & & & & & & \(\times\) & \(\times\) & \\ Tetradecanal & 124-25-4 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Pentadecanal & 2765-11-9 & & & & \(\times\) & & & & \(\times\) \\ Tetradecanoic acid & 544-63-8 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Pentadecanoic acid & 1002-84-2 & & \(\times\) & \(\times\) & & & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\
9-Hexadecenoic acid & 2091-29-4 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ _n_-Hexadecanoic acid & 57-10-3 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Isopropyl palmitate & 142-91-6 & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) & \(\times\) \\ Octadecanoic acid & 57-11-4 & & & & & & & & \(\times\) \\ Squalane * & 111-01-3 & \(\times\) & & \(\times\) & \(\times\) & \(\times\) & & \(\times\) & \(\times\) \\ \hline \hline \end{tabular}  
* \({}^{*}\)Tentative identification, retention index (RI) match \(>\)10 RI units.  
\end{table} 
Table 1: Compounds identified in the skin headspace of human participants after 15 min sample collection using a wearable concentration method employing headspace solid-phase microextraction (HS-SPME) followed by thermal desorption to gas chromatography-mass spectrometry (GC-MS). Compounds are shown in order of increasing retention time, where \(\times\) indicates the presence of a compound in a sample. (F—female, M—male). Figure 1: Overlaid total ion chromatograms showing recovered skin volatiles. **(A)** The baseline skin volatile profile; **(B)** the volatile profile immediately after fragrance application; **(C)** skin volatiles 1 h after fragrance application and **(D)** 2 h after fragrance application. This approach can provide an insight into the longevity of individual fragrance components on skin.