Table 2.

Reproducibility of retention times across the entire calibration curves for AccQ•Tag derivatized physiological amino acid standards, and isotopically labeled amino acids, analyzed by UPLC-MS/MS. Experimental conditions were the same as in Table 1.

Amino acid	MRM transition	Function #	Average RT (min)	STD	CV (%)
Hydroxy-L-proline	302.11 > 171	1	1.61	0.02	1.08
Histidine (ring 2-13C)	327.21 > 171	1	1.71	0.02	0.09
L-Histidine	326.21 > 171	1	1.70	0.01	0.68
1-Methyl-histidine	340.21 > 171	1	2.06	0.02	0.74
Taurine	296.11 > 171	1	2.19	0.02	0.79
3-Methyl-histidine	340.21 > 171	1	2.30	0.01	0.5
Serine-2,3,3-d3	279.11 > 171	1,2	2.60	0.01	0.38
L-Serine	276.11 > 171	1,2	2.63	0.01	0.47
Arginine (guanido-15N2)	347.36 > 171	2	3.99	0.01	0.14
L-Arginine	345.21 > 171	2	2.86	0.02	0.58
Glycine-d5	248.25 > 171	2	2.99	0.01	0.19
Glycine	246.08 > 171	2	3.01	0.01	0.33
L-Carnosine	397.21 > 171	2	2.84	0.01	0.39
Ethanolamine	232.09 > 171	2	3.16	0.01	0.27
L-Asparagine-15-N2	305.27 > 171	2	3.39	0.01	0.17
L-Aspartic acid	304.11 > 171	2	3.38	0.01	0.27
L-Sarcosine	260.17 > 171	2	3.83	0.01	0.13
Citrulline-ureido-13C	347.35 > 171	2	3.99	0.01	0.14
L-Glutamic acid-2,4,4-d3	321.11 > 171	2	3.96	0.01	0.15
L-Glutamic acid	318.11 > 171	2	3.97	0.01	0.19
L-Citrulline	346.21 > 171	2	3.99	0.01	0.15
β-Alanine	260.17 > 171	2,3	4.20	0.01	0.18
Threonine-d5	295 > 171	3	4.43	0.01	0.13
L-Threonine (13C, 15N)	295.11 > 171	3	4.43	0.01	0.13
L-Threonine	290.11 > 171	3	4.43	0.01	0.13
L-Alanine	260.1 > 171	3	4.86	0.01	0.15
D-L-Alanine-2,3,3,3-d4	264.11 > 171	3	4.86	0.01	0.12
γ-Amino-n-butyric acid	274.11 > 171	3	5.03	0.01	0.12
Amino adipic acid	332 > 171	3	5.24	0.00	0.08
D-L-β-Aminoisobutyric acid	274.11 > 171	3	5.48	0.01	0.27
Proline-2,5,5-d3	289 > 171	3	5.49	0.01	0.11
L-Proline	286.16 > 171	3	5.51	0.03	0.58
δ-hydroxylysine	33.21 > 171	3	5.23	0.01	0.23
L-α-Amino-n-butyric acid	274.11 > 171	3	6.09	0.02	0.33
Ornitine-3,3,4,4,5,5-d6	479.22 > 171	4	6.19	0.02	0.37
L-Ornitine	303.21 > 171	4	6.20	0.01	0.08
L-Lysine	317.21 > 171	4	6.60	0.01	0.19
4-Hydroxyphenyl-2,6-d2-alanine-2-d1-01	355.22 > 171	4	6.68	0.01	0.09
Tyrosine	352.21 > 171	4	6.69	0.01	0.01
Methionine-methyl-d3	323.13 > 171	4	6.83	0.01	0.08
L-Methionine	320.21 > 171	4	6.86	0.05	0.7
Valine-d8	296.11 > 171	4	6.95	0.01	0.08
L-Valine	288.21 > 171	4	6.98	0.01	0.09
L-Isoleucine	302.21 > 171	5	7.73	0.02	0.19
Leucine-d10	312.24 > 171	5	7.78	0.01	0.07
L-Leucine	302.21 > 171	5	7.82	0.03	0.40
Phenyl-d5-alanine	341.21 > 171	5	7.92	0.02	0.26
Phenyl-alanine	336.21 > 171	5	7.92	0.01	0.12
Tryptophan-2′,4′,5′,6′,7′-d5(indole-d5)-01	380.21 > 171	5	8.01	0.01	0.07