Table 1.

Relative standard deviation (RSD) values in intra-day and inter-day precision tests of the developed method.

Analyte	Sample	Intra-Day Precision (n = 5)			Inter-Day Precision (n = 5)
		RT 1 (min), %RSD 2	Peak Area, %RSD 2	Conc 3, %RSD 2	RT 1 (min), %RSD 2	Peak Area, %RSD 2	Conc 3, %RSD 2
Proline	QC1	0.04	2.95	0.18	0.92	10.53	0.66
	QC2	0.74	7.25	1.29	0.69	6.21	0.84
	QC3	1.06	7.13	1.71	0.78	6.07	1.24
Arginine	QC1	0.14	6.85	3.34	0.15	14.27	5.67
	QC2	0.18	1.59	12.41	0.23	4.98	8.46
	QC3	0.07	4.01	14.97	0.14	5.25	10.26
Glutamic acid	QC1	0.23	6.12	4.87	0.33	7.27	5.19
	QC2	0.45	8.04	0.92	0.41	5.21	3.61
	QC3	0.31	5.65	3.40	0.33	4.17	3.68

¹ RT—retention time; ² RSD—relative standard deviation; ³ Conc—concentration value.