. Author manuscript; available in PMC: 2008 Jun 1.

Published in final edited form as: J Chromatogr B Analyt Technol Biomed Life Sci. 2007 Feb 21;852(1-2):554–561. doi: 10.1016/j.jchromb.2007.02.024

Table 1.

Intra- and inter-day precision and accuracy for HCY and CYS

	Concentration (μM)		% RSD	% Bias
	Spiked	Measured (mean ± SD)
Intra-assay reproducibility^a
Quality Controls
HCY	4.0	3.8 ± 0.1	2.9	−5.5
	16.0	16.2 ± 0.4	2.5	1.4
	80.0	80.5 ± 1.6	2.0	0.6
CYS	32.5	31.4 ± 0.4	1.4	−3.2
	130.0	132.5 ± 3.2	2.4	1.9
	650.0	645.3 ± 13.3	2.1	−0.7
Inter-assay reproducibility^b
Quality Controls
HCY	4.0	3.8 ± 0.3	7.9	−4.5
	16.0	16.1 ± 0.7	4.3	0.9
	80.0	81.6 ± 3.4	4.2	2.0
CYS	32.5	31.8 ± 1.9	5.8	−2.3
	130.0	131.7 ± 6.0	4.6	1.3
	650.0	657.8 ± 31.5	4.8	1.2
Standards
HCY	3.13	3.2 ± 0.1	3.3	0.7
	6.25	6.4 ± 0.2	3.2	2.1
	12.5	13.0 ± 0.2	1.7	3.9
	25.0	22.9 ± 0.5	2.4	−8.3
	50.0	50.9 ± 0.2	0.5	1.9
	100.0	100.7 ± 0.6	0.6	0.7
CYS	25.0	25.8 ± 0.7	2.5	3.2
	50.0	50.0 ± 1.1	2.3	0.0
	100.0	100.5 ± 1.1	1.1	0.5
	200.0	186.0 ± 4.7	2.5	−7.0
	400.0	406.0 ± 4.2	1.0	1.5
	800.0	807.8 ± 5.5	0.7	1.0

Twelve quality control samples per concentration.

Six to twelve quality control samples or two standards per day per concentration for three days.