## 2 Results and Discussion
### Identification of ARR VOCs In Vivo in Rats
\begin{table}
\begin{tabular}{l c c c c c c} \hline \hline
**No. a** & **Name of Compounds** & **CAS b** & **tR (min)** & **MW c** & **Formula** & **RI d** & **Identification e** \\ \hline
**M126** & Methoxyeugenol isomer & & 47.835 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2441 & MS \\
**M127** & Kakuol isomer & & 47.895 & 194 & C\({}_{10}\)H\({}_{10}\)O\({}_{4}\) & 2446 & MS \\
**M128** & Mellein & 1200-93-7 & 48.255 & 178 & C\({}_{10}\)H\({}_{10}\)O\({}_{3}\) & 2475 & MS, RI \\
**M129** & 2,4-Dimethoxyacetophenone & 829-20-9 & 48.345 & 180 & C\({}_{10}\)H\({}_{12}\)O\({}_{3}\) & 2483 & MS \\
**M130** & 2,6-Dimethoxyacetophenone & 2040-04-2 & 48.585 & 180 & C\({}_{10}\)H\({}_{12}\)O\({}_{3}\) & 2503 & MS \\
**M131** & 1-(3,4-Methylenedioxyphenyl)- & 6890-30-8 & 48.777 & 180 & C\({}_{10}\)H\({}_{12}\)O\({}_{3}\) & 2521 & MS \\
**M132** & Piperenol & 495-76-1 & 48.928 & 152 & C\({}_{8}\)H\({}_{8}\)O\({}_{3}\) & 2534 & MS \\
**M133** & Methoxyeugenol isomer & & 48.935 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2534 & MS \\
**M134** & 3-Methyloxy-5-methylphenol & 3209-13-0 & 48.985 & 138 & C\({}_{8}\)H\({}_{10}\)O\({}_{2}\) & 2538 & MS, RI \\
**M135** & 2\({}^{\prime}\),\({}^{\prime}\)A\({}^{\prime}\)-Dimethoxypropiophenone & 831-00-5 & 49.045 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2544 & MS \\
**M136** & 4,6-Dimethoxy-phthalide & 58545-97-4 & 49.065 & 194 & C\({}_{10}\)H\({}_{10}\)O\({}_{4}\) & 2546 & MS \\
**M137** & Methoxyeugenol & 6627-88-9 & 49.069 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2547 & MS, RI \\
**M138** & Kakuol & 18607-90-4 & 49.295 & 194 & C\({}_{10}\)H\({}_{10}\)O\({}_{4}\) & 2567 & MS, REF \\
**M139** & 2\({}^{\prime}\),\({}^{\prime}\)A\({}^{\prime}\)-Dimethoxy-3\({}^{\prime}\)- & & 49.690 & 208 & C\({}_{12}\)H\({}_{16}\)O\({}_{3}\) & 2602 & MS \\
**M140** & Xanthoxylin & 90-24-4 & 49.760 & 196 & C\({}_{10}\)H\({}_{10}\)O\({}_{4}\) & 2608 & MS \\
**M141** & 3,4-Methylenedioxyphenyl-1- & 30830-55-8 & 49.915 & 178 & C\({}_{10}\)H\({}_{10}\)O\({}_{3}\) & 2620 & MS \\  & propanal & & 50.226 & 208 & C\({}_{12}\)H\({}_{16}\)O\({}_{3}\) & 2645 & MS \\
**M142** & 2\({}^{\prime}\),\({}^{\prime}\)A\({}^{\prime}\)-Dimethoxy-3\({}^{\prime}\)- & & 592.70 & 224 & C\({}_{12}\)H\({}_{16}\)O\({}_{4}\) & 2648 & MS \\
**M143** & 3,4,5-Trimethoxyphenyl-2-propanone & 16603-18-2 & 50.270 & 224 & C\({}_{12}\)H\({}_{16}\)O\({}_{4}\) & 2648 & MS \\
**M144** & 4-(Dimethoxymethyl)-1,2- & 59276-33-4 & 50.615 & 212 & C\({}_{11}\)H\({}_{16}\)O\({}_{4}\) & 2676 & MS \\  & dimethoxybenzene & 1835-04-7 & 50.740 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2686 & MS \\
**M146** & 2\({}^{\prime}\),\({}^{\prime}\)A\({}^{\prime}\)-Dimethoxypropiophenone & 831-00-5 & 50.760 & 194 & C\({}_{11}\)H\({}_{14}\)O\({}_{3}\) & 2687 & MS \\
**M147** & Dihydromethyleugenol & 5888-52-8 & 51.135 & 180 & C\({}_{11}\)H\({}_{16}\)O\({}_{2}\) & 2714 & MS \\
**M148** & 2\({}^{\prime}\),\({}^{\prime}\)A\({}^{\prime}\)-Dimethoxy-3\({}^{\prime}\)- & & & & & \\
**M149** & methylpropiophenone & 77942-13-3 & 51.435 & 208 & C\({}_{12}\)H\({}_{16}\)O\({}_{3}\) & 2734 & MS \\
**M149** & 1-Hydroxy-2-(prop-2-enyl)-4,5- & 19202-23-4 & 51.670 & 178 & C\({}_{10}\)H\({}_{10}\)O\({}_{3}\) & 2750 & MS \\  & methylenedioxybenzene & & & & & \\
**M150** & 3-(2,4,6-Trimethoxyphenyl)- & 26537-69-9 & 51.850 & 238 & C\({}_{13}\)H\({}_{18}\)O\({}_{4}\) & 2761 & MS \\
**M151** & 1,2-Dimethoxy-4-(1,2-dimethoxy & & & & & \\
**M152** & 1-Hydroxy-2-(prop-2-enyl)-4,5- & & & & & \\
**M153** & Syringic acid & 530-57-4 & 55.055 & 198 & C\({}_{9}\)H\({}_{10}\)O\({}_{5}\) & 2934 & MS \\ \hline \hline \end{tabular}  
* Compounds identified in feces, urine, blood, and eight organ samples (brain, heart, lung, spleen, liver, kidney, stomach, and small intestine) are sorted by retention time (tR), and their polarity increases with prolonged retention time. b CAS: Chemical Abstracts Service. c MW: molecular weight. d RI: calculated based on C\({}_{7}\)–C\({}_{30}\) saturated alkanes. e Identification: MS: searching mass spectra in NIST 11 (version 2011, National Institute of Standards and Technology, USA) library embedded in GC-MS workstation (GCMS solutions, version 2.71, Shimadzu, Kyoto, Japan); RI: comparing retention index (RI) and mass spectra with literature; REF: comparing retention time and mass spectra with reference compounds.  
\end{table}