Table 3.

Correlation coefficient of determination, linear range, the limit of quantitation (LOQ), the limit of detection (LOD), spike recovery, and precision of the mixed stock standard solution of 20 free amino acids (FAAs) and glutathione (GSH).

Analytes	Correlation Coefficient of Determination (R2)	Linear Range (µmol·L−1)	LOQ (µmol·L−1)	LOD (µmol·L−1)	Average Spike Recovery (%)	Precision (%RSD, n = 5)
						Intra-Day	Inter-Day
Tau	0.9992	0.40~58.20	0.38	0.10	90.42	0.46	1.23
GSH	0.9994	0.35~30.21	0.30	0.12	88.26	0.51	1.82
Asp	0.9993	0.65~60.32	0.60	0.20	94.25	0.52	1.63
Thr	0.9997	0.75~64.72	0.52	0.22	95.38	0.53	1.68
Ser	0.9991	0.74~65.85	0.74	0.24	87.61	0.71	2.10
Glu	0.9999	0.86~68.92	0.83	0.23	92.33	0.71	2.35
Gly	0.9993	0.85~67.62	0.85	0.27	100.80	0.38	1.32
Ala	0.9997	0.91~78.64	0.91	0.25	87.31	0.36	1.26
Cys	0.9992	1.12~75.82	0.67	0.16	87.92	0.67	2.38
Val	0.9993	1.05~73.16	0.94	0.25	86.42	0.46	1.53
Met	0.9996	0.65~68.59	0.54	0.12	89.57	0.53	1.85
Ile	0.9994	0.85~81.57	0.76	0.23	99.25	0.62	2.10
Leu	0.9992	0.72~83.24	0.60	0.13	102.33	0.31	1.63
Tyr	0.9996	0.54~63.84	0.21	0.07	95.79	0.56	1.94
Phe	0.9993	0.61~68.43	0.43	0.16	103.64	0.61	2.32
Orn	0.9991	0.52~56.16	0.52	0.19	95.10	0.37	1.74
Lys	0.9993	0.47~55.63	0.47	0.12	89.32	0.46	1.83
His	0.9998	0.84~68.37	0.80	0.27	87.67	0.35	1.82
Arg	0.9997	0.82~88.49	0.65	0.19	87.56	0.39	1.42
Hyp	0.9994	0.80~79.65	0.72	0.18	99.51	0.52	1.82
Pro	0.9992	2.40~98.36	2.40	0.73	92.19	0.62	2.01