Table 1. Validation data for selected amino acids in human plasma with the optimized CE-LIF method.

	L-proline	L-isoleucine	L-ornithine	L-glutamine	L-alanine	L-threonine	glycine	L-serine	D-serine	L-glutamate
Linearity (N=20)
Slope	0.0078 ± 0.0003	0.0059 ± 0.0004	0.0017 ± 0.0002	0.0048± 0.0003	0.00382 ± 8.4E-05	0.0052 ± 0.0003	0.0059 ±0.0004	0.0055 ± 0.0003	0.0047 ± 0.0002	0.00481 ± 0.00003
Intercept	−0.075 ± 0.099	−0.053 ± 0.067	−0.020 ± 0.028	−0.37 ± 0.27	−0.028 ± 0.038	−0.19 ± 0.12	−0.012 ± 0.0179	−0.21 ± 0.13	0.0004 ± 0.003	0.012 ± 0.012
r	0.997	0.992	0.991	0.997	0.999	0.997	0.995	0.996	0.998	0.9997
Range (μM)	25-300	25-300	25-300	125-1500	25-750	25-600	25-750	25-750	0.5-25	25-300
Accuracy
%	97.1	101.5	97.1	101.8	94.0	96.0	96.7	103.7	100.9	92.0
RSD(%)	3.7	5.2	6.9	4.5	7.76	7.3	6.0.	6.2	4.5	9.8
Instrumental precisión (N=12) RSD(%) Method Precision Standard	4.3	2.2	4.3	5.2	1.4	5.9	4.3	5.6	4.8	1.6
Inter-assay (N=12) RSD (%)	6.5	4.2	6.8	6.2	3.8	5.5	5.2	6.7	4.4	2.8
Intra-assay (N=6) RSD (%) Method Precision Sample	3.1	3.5	2.9	3.2	3.6	3.7	3.7	3.3	2.7	3.0
Inter-assay (N=12) RSD (%)	6.0	5.3	6.0	5.7	5.8	5.5	4.4	5.3	6.8	3.4
Intra-assay (N=6) RSD (%)	5.4	5.2	4.0	5.6	2.0	2.9	2.8	5.1	5.0	2.0
LOQ (EURACHEM)(nM)	738	630	1.44 μM	146	889	714	128	174	231	203
LOD(nM)	221	189	433	43.7	267	214	38.3	52.2	69.5	61.0