Table 2. Precision of SB-PS-MS Analysis: Intra-Day Analysis was Conducted with Three Triplicates Measured on Three Different Days.

AA	intra-day
	day 1	day 2	day 3
	RSD (%)	RSD (%)	RSD (%)
Gly	4.4	5.0	0.6
Ala	2.7	3.5	1.4
Ser	15	15	1.0
Pro	2.8	3.3	1.6
Val	2.0	1.8	0.9
Thr	14	6.7	1.8
Leu + Ile	3.9	12	0.9
Asp	16	9.5	12
Lys	27	37	12
Glu	59	69	25
Met	16	36	9.5
His	38	38	23
Phe	3.8	1.2	5.9
Arg	13	11	6.9
Tyr	11	2.0	9.1