# Chemical Characterization of Human Body Odor Headspace Components
## 3 Results
### Whole-Body Sampling
\begin{table}
\begin{tabular}{l l l l l l} \hline \hline
**Functionality** & **Compound Name** & **Chamber** & **Hand** & **Axillary** & **Breath** & **Cited in** \\ \hline Alcohols & 7-Octen-2-ol, 2,6-dimethyl- & 70\% & & 40\% & \\ \hline  & Benzyl alcohol & 60\% & 80\% & & [2;3,17,18,21,22,25; 26; 27; 28] \\ \hline  & Linalool & 80\% & 10\% & 10\% & \\ \hline Aldehydes & 3-(4-Isopropylphenyl)-2- methylpropionaldehyde & 60\% & & & \\ \hline  & Benzaldehyde & 50\% & 40\% & & [2;3,10,17,18,22,25,26,29,30] \\ \hline  & Decanal & 100\% & 100\% & 80\% & 40\% & [2;3,6,10,17,18,21,22,25; 26; 27; 29; 30; 31; 32; 33] \\ \hline  & Nonanal & 90\% & 100\% & 70\% & 30\% & [2;3,6,10,17,18,21,22,25; 26; 27; 29; 31; 32; 33] \\ \hline  & Octanal, 2-(phenylmethylene)- & 70\% & 30\% & & [31; 32] \\ \hline Esters & 4-tert-Butylcyclohexyl acetate & 60\% & & 40\% & [7; 31] \\ \hline  & Isobornyl acetate & 60\% & 20\% & 30\% & \\ \hline  & Pentanedio acid, dimethyl ester & 60\% & & & \\ \hline  & Propanoic acid, 2-methyl-, & 3-hydroxy-2,2,4-trimethylpentyl ester & 80\% & & [31] \\ \hline Heterocyclics & Benzene, (1-pentylheptyl)- & 70\% & 10\% & & [31] \\ \hline  & Cyclopent[g]-2-benzopyran, & & & \\  & 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- & 70\% & 20\% & 20\% & \\  & hexamethyl- & & & \\ \hline Hydrocarbons & D-Limonene & 50\% & & 10\% & [17; 22; 34; 35] \\ \hline  & Hexadecane & 100\% & 90\% & & [2;3,18,21,22,26; 27; 28; 30; 32] \\ \hline  & Naphthalene, 2-methoxy- & 90\% & 60\% & & \\ \hline  & Nonane, 2,2,4,4,6,8,8-heptamethyl- & 50\% & 30\% & & \\ \hline  & Tetradecane & 100\% & 70\% & 10\% & [2;3,17,18,21,22,25; 26; 27; 28; 30] \\ \hline Ketones & 1-(4-tert-Butylphenyl)propan-2-one & 70\% & & & \\ \hline  & 5-Hepten-2-one, 6-methyl- & 100\% & 70\% & 10\% & [2;3,10,17,21,22,28,30,31,33] \\ \hline  & 5,9-Undecadien-2-one, & & & & \\  & 6,10-dimethyl-, (E)- & 70\% & 60\% & & [3; 17; 18; 22; 27; 30] \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Human scent compounds detected from each sample type and frequency of occurrence. ten (10) subjects, one hundred five (105) VOCs were detected from the chamber (whole-body), seventy-six (76) were detected among the hand samples, seventy-three (73) were detected within the axillary samples, and ten (10) compounds were detected from the breath samples. Within the chamber samples, alcohols (24%) contributed the most to the chemical composition, followed by hydrocarbons and esters, with both contributing 19% to the overall composition. Those functional groups with the lowest distributions included ethers, acids, and aldehydes. With respect to the hand samples, the largest contributing group was alcohols (28%), followed by hydrocarbons (25%) and heterocyclics (12%). The groups with the lowest distribution percentage included sulfones, acids, and ethers. Within the axillary samples, hydrocarbons (30%) had the largest distribution, followed by heterocyclics (25%) and alcohols (16%). Ethers, aldehydes, and ketones contributed the least to the overall chemical composition of these samples. Among the breath samples, only five (5) functional groups were identified, with hydrocarbons (40%) having the largest distribution, followed by aldehydes (30%). The remaining three functional groups--ketones, alcohols, and heterocyclics--each contributed 10% to the overall composition. This information can be seen in further detail in Table 1, which lists the individual compounds identified within this study, classifies them by functional group, and includes the percent frequency observed within each sample type (chamber, hand, axillary, breath). Across these four distinct sample types, the ratios of each functional group varied; however, hydrocarbons appeared to be prominent across the board. Similar studies that analyzed the human scent VOCs released from different biospecicns such as hand odor, hair, fingernails, saliva, breath, urine, and blood also reported that hydrocarbons were prominent in chemical odor characterization of the different specimens [3; 27].