Table 3.

Chromsystems external calibrators.

25OHD3				25OHD2
Chromsystems concentration (ng/mL)	Measured Concentration (ng/mL)	%DEV		Chromsystems concentration (ng/mL)	Measured Concentration (ng/mL)	%DEV
4.50	6.245	38.8		n.d	1.98
9.70	8.967	−7.6		5.00	5.03	2.8
18.50	19.176	3.7		14.30	14.69	2.7
32.90	30.959	−5.9		28.60	27.75	−3.0
65.60	67.321	2.6		57.10	65.56	14.8
102.00	101.078	−0.9		98.60	106.90	8.4
140.00	146.574	4.7		140.00	158.06	12.9
QC (acceptable range 36.0-54.1 ng/mL)				QC (acceptable range 29.6-44.4 ng/mL)
45.1	42.772			37.0	37.25
45.1	48.372			37.0	40.99
45.1	47.769			37.0	38.38
45.1	44.178			37.0	33.37
45.1	47.463			37.0	35.36
	%CV = 4.8				%CV = 12.3