Table 2. The retention time, molecular weight, and MS data of the identified peaks.

No.	Compounds	RT (min)	MW	MS
1	l-Carnitine	0.77695	161.2	162.1129
2	LPC 16:0	26.34937	495.63	496.3426
3	Coumaroyl tyramine	13.11965	283.32	284.1285
4	Tetramethylpyrazine	4.503284	136.19	137.111
5	LPC 18:1	27.22265	521.3	522.3564
6	Choline	0.8071333	104.17	104.1091
7	(S,S)-Butane-2,3-diol	12.07172	90.12	73.06499
8	Scopoletin	6.421317	192.17	193.0511