## 4 Discussion
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Lion Urine**} & \multicolumn{2}{c}{**Tiger Urine**} & \multicolumn{2}{c}{**Cu Urine**} & \multicolumn{2}{c}{**Suine Maunere**} & \multicolumn{2}{c}{**Cages**} & \multicolumn{2}{c}{**Cu Urine-Capped (Bank)**} & \multicolumn{1}{c}{**Current**} \\
**Compounds** & **CAS*** & **([PERSON] and [PERSON], 2017)(121)** & **([PERSON] and [PERSON], 2016)** & **([PERSON], 2000)** [4]** & **([PERSON] et al., 2008)** [22]** & **([PERSON] et al., 2019)** [23]** & **at al., 2020)** [18]** & **Study** \\ \hline Phenol & 108-95-2 & X & X & X & X & X & X & X \\ P-Cresol & 106-44-5 & X & X & X & X & X & & X \\ Phenol, 4-ethyl- & 123-07-0 & & & X & & & X \\
3-Octanol & 589-96-0 & & & & X & & & X \\
1-butanol & 77-36-3 & X & & X & X & & X \\
1-Heanel & 111-27-3 & X & & X & X & X & X \\ Benzyl alcohol & 100-51-6 & & & X & X & & X \\
3-bromo-1-ol.3-methyl- & 763-32-6 & & X & & & X & \\ Benzene enhancer & 601-28 & X & & X & & & X \\ Dimethyl disulfide & 64-92-0 & X & & & X & & \\ DTTurkyline & 67-71-0 & & & X & & & X \\ Benzaldehyde & 100-52-7 & X & X & X & X & & X \\ Butananan, 3-methyl- & 900-86-3 & X & X & & & X & \\ Isobutyrate/aldehyde & 78-84-2 & & & & & X & \\ Timothy amine & 75-50-3 & X & X & & & & X \\
2-D-Dodecanone & 675-48-1 & & & X & & & X \\
2-Diterpene & 101-43-0 & & X & & X & & X \\
2-Dependence & 101-43-0 & & & X & & & X \\
3-methyl-2-pentrance & 565-47-2 & & & & X & & X \\
2-bitanone & 78-93-3 & X & X & X & X & & \\
3-nitroborne & 67-44-1 & X & X & X & & & X \\
5-HPEPE-3-one, demethyl-3 & 110-90-0 & & & & X & & X \\ Acetosphere & 98-65-2 & & & & X & & X \\ Jamone & 488-10-8 & & & X & & & X \\ Indide & 120-72-9 & x & & & X & & \\
3-methyl/indindigo & 95-20-5 & & & X & & & X \\ Pyrazine, 23 dimethyl- & 108-80 & & X & & & & X \\ Aortic acid & 61-97- & & & X & & X & \\ Butananico acid & 100-92-6 & & & X & & & \\ Pentunc acid & 4,methyl- & 79-31-2 & & & & X & \\ Butanico acid & 3,503-742 & & & & X & & \\ Pentunc acid & 100-88-4 & & & & X & & \\ Propine acid & 79-04 & & & & X & & \\ Hexanoic acid & 142-62-1 & & & & & & X \\ Butanica acid & 503-742 & & & & & & \\ Carbon disulfide & 75-15-60 & & & & X & & \\ Butanico acid, ethyl ester & 105-54-4 & & & & X & & \\ \hline \hline \end{tabular} CAS*** = Chemical Abstracts Service X represents the VOCs common to this study and previously published work.  
\end{table} 
Table 4: Some literature recorded the VOCs emitted from urine, feces, and fruits of different biological species commonly found that are also in the current study. Many VOCs emitted from the cat feces samples, as reported in this study, were also reported to be emitted from swine manure samples [22]. In addition, a few VOCs extracted by SPME and reported in this study are found to be common in the SPME extraction from cold-hardy grape samples [23]. The characteristic odor compound 2,5 dimethyl pyrazine from lion and cat urine indicates the evolutionary similarities between animals. Chemicals such as phenol and p-cresol in human urine are important biomarkers, and they are challenging to measure due to their presence at a low detection limit [24]. However, the use of GC-MS-O can verify their presence by their distinct \"ruinous\" or \"barnyard\" odor even at trace levels (Figures 3 and 4). These observations also indicate the fact that SPME in a combination of GC-MS-O for the headspace extraction is better suited for assessing odor than only GC-MS. Overall, SPME reduces the sampling time for volatile or semi-volatile compound determination compared to a traditional sampling technique [25], and this technology can be developed more for future assessment of quantitative analysis of these odorous constituents characteristic to the overall smell of urine or feces sample. Several VOCs were common in urine and feces samples, such as acetone, 2-butanone, 3-methyl butanal, 3 methyl 2-pentanone, phenol, p-cresol, and indole. Chemicals such as phenol and indole are commonly produced by cat species irrespective of their sex and age [8; 10].