## 3 Experimental Results
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline  & \multicolumn{2}{c}{_5 LOD_} & \multicolumn{2}{c}{_5 LOQ_} & \multicolumn{2}{c}{_10 LOD (ng)_} & \multicolumn{2}{c}{_10 LOQ_} & \multicolumn{2}{c}{_20 LOD_} & \multicolumn{2}{c}{_20 LOQ_} \\ \cline{2-7}  & _(ng)_ & _(ng)_ & _(ng)_ & _(ng)_ & _(ng)_ & _(ng)_ \\ \hline _Compound_ _Intraday RSD \%_ & _Interday RSD \%_ & _Intraday RSD \%_ & _Interday RSD \%_ & _Intraday RSD \%_ & _Interday RSD \%_ & _Interday RSD \%_ \\ _Common Name_ & _(n = 3)_ & _(n = 21)_ & _(n = 3)_ & _(n = 21)_ & _(n = 3)_ & _(n = 21)_ \\ \hline
2-butanone & 5 \(\pm\) 1 & 12 \(\pm\) 1 & 6 \(\pm\) 1 & 10 \(\pm\) 1 & 3 \(\pm\) 1 & 11 \(\pm\) 1 \\ \hline
3-heptanone & 6 \(\pm\) 1 & 10 \(\pm\) 1 & 4 \(\pm\) 1 & 11 \(\pm\) 3 & 5 \(\pm\) 1 & 10 \(\pm\) 3 \\ \hline
1-Octine & 7 \(\pm\) 1 & 12 \(\pm\) 2 & 6 \(\pm\) 2 & 11 \(\pm\) 3 & 8 \(\pm\) 2 & 11 \(\pm\) 2 \\ \hline Acetonitrile & 3 \(\pm\) 1 & 14 \(\pm\) 2 & 3 \(\pm\) 1 & 14 \(\pm\) 2 & 4 \(\pm\) 1 & 13 \(\pm\) 3 \\ \hline Benzaldehyde & 7 \(\pm\) 2 & 13 \(\pm\) 2 & 8 \(\pm\) 3 & 12 \(\pm\) 3 & 5 \(\pm\) 2 & 13 \(\pm\) 2 \\ \hline Butanoic acid & 5 \(\pm\) 1 & 11 \(\pm\) 1 & 3 \(\pm\) 1 & 10 \(\pm\) 2 & 5 \(\pm\) 1 & 12 \(\pm\) 2 \\ \hline Butanol & 7 \(\pm\) 1 & 11 \(\pm\) 1 & 5 \(\pm\) 1 & 10 \(\pm\) 1 & 6 \(\pm\) 2 & 11 \(\pm\) 1 \\ \hline Decane & 4 \(\pm\) 1 & 8 \(\pm\) 1 & 6 \(\pm\) 1 & 8 \(\pm  
Overall, seventy-four VOCs were detected (S/N \(\geq\) 3), while sixty-seven were identified and these are reported in Table 6. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline _Peak n\({}^{\circ}\)_ & _RT a (min)_ & _Common Compound Name_ & _Match (\%)_ & _Probability (\%)_ & _Standard identity Confirmation b_ & _Healthy Subjects_ & _CKD Patients_ \\ \hline
1 & 4.2 & Unidentified & & & & yes & \\ \hline
2 & 5.7 & Carbon dioxide & 891 & 90 & & yes & yes \\ \hline
3 & 6.4 & 2,4-Dimethyl pentane & 930 & 91 & & yes & yes \\ \hline
4 & 6.5 & Hexene & 879 & 89 & & yes & yes \\ \hline
5 & 6.6 & Sulfur dioxide & 878 & 87 & & yes & yes \\ \hline
6 & 6.7 & Difluoro methyl-silane & 801 & 52 & & yes & yes \\ \hline
7 & 6.8 & Trimethyl silylanol & 773 & 55 & & yes & yes \\ \hline
8 & 6.9 & Ethane, 1,2-diethoxy & 801 & 61 & & yes & yes \\ \hline
9 & 7.0 & 1-Pentene-4-methyl & 822 & 54 & & yes & yes \\ \hline
10 & 7.2 & 2-propane & 833 & 60 & yes & yes & yes \\ \hline
11 & 7.6 &
\begin{tabular}{c} 1,1,1,1-Trifluoro \\ trimethyl-silylanol \\ \end{tabular} & 828 & 56 & & yes & yes \\ \hline
12 & 7.9 & Cyclobutanolo & 903 & 78 & & yes & yes \\ \hline
13 & 8.3 &
\begin{tabular}{c} Trichloro-monofluorororor \\ methane \\ \end{tabular} & 822 & 57 & & yes & yes \\ \hline
14 & 8.9 & 1,3-Pentadiene & 954 & 75 & & yes & yes \\ \hline
15 & 9.1 & 2-Propanol-1-methoxy & 930 & 80 & & yes & yes \\ \hline
16 & 9.7 & Unidentified & & & yes & yes \\ \hline
17 & 10.1 & 2-Pentene & 915 & 85 & & yes & yes \\ \hline
18 & 10.2 & 2-Butanol-3-methyl & 907 & 84 & & yes & yes \\ \hline
19 & 10.3 & 2-Methyl pentanal & 839 & 58 & & yes & yes \\ \hline
20 & 10.5 & Cyclopentane & 903 & 88 & & yes & yes \\ \hline
21 & 10.7 & **Propylamine** & & 55 & yes & & yes \\ \hline
22 & 10.8 & 2,3-Dimethyl pentane & & 66 & & yes & yes \\ \hline
23 & 10.9 & Hexane & 913 & 92 & yes & yes & yes \\ \hline
24 & 11.0 & 4-Methyl-2-pentyne & 877 & & & yes & yes \\ \hline
25 & 11.4 & **Acetonitrile** & 920 & 90 & yes & & yes \\ \hline
26 & 11.5 & Unidentified & & & yes & yes \\ \hline
27 & 11.6 & Benzene & 938 & 89 & yes & yes & yes \\ \hline
28 & 11.8 & Methoxy-acetonitrile & 888 & 56 & & & yes \\ \hline
29 & 12.2 & **Ethylenediamine** & 815 & 52 & yes & & yes \\ \hline
30 & 12.4 & Unidentified & & & yes & yes \\ \hline
31 & 12.9 & 1,3,5-Trifluoro benzene & 852 & 57 & & yes & yes \\ \hline
32 & 13.2 & **Dichloromethane** & 931 & 93 & yes & yes & yes \\ \hline
33 & 13.5 & Hexamethyl disiloxane & 828 & 81 & & yes & yes \\ \hline
34 & 13.6 & Xylitol & 876 & 83 & & yes & yes \\ \hline
35 & 13.7 & Phenol & 913 & 92 & yes & yes & yes \\ \hline \hline \end{tabular}
\end{table}