Table 2.

Accuracy and precision (intra and inter-day) evaluation.

Samples	Standard method average ng mL −1	Intra-day accuracy and precision (n = 3)					Inter-day accuracy and precision (n = 3)
		Average recovered ng mL −1a ± CL			RE%	RSD%	Average recovered ng mL −1 ± CL			RE %	RSD%
Patient (1)	8.3	8.3	±	0.001	−0.2	0.01	8.2	±	0.001	1.3	0.01
Patient (2)	3.5	3.5	±	0.002	−0.5	0.02	3.5	±	0.002	−0.2	0.02
Patient (3)	9.1	9.2	±	0.001	−0.6	0.01	9.2	±	0.001	−1.1	0.01
Patient (4)	1.2	1.2	±	0.003	0.0	0.07	1.3	±	0.003	−8.3	0.06
Patient (5)	13.7	13.7	±	0.001	0.4	0.01	13.5	±	0.001	1.4	0.01
Patient (6)	2.4	2.4	±	0.002	0.8	0.03	2.4	±	0.002	0.0	0.03
Patient (7)	6.4	6.4	±	0.001	0.2	0.01	6.3	±	0.001	0.7	0.01
Patient (8)	9.8	9.8	±	0.001	0.10	0.01	9.8	±	0.001	0.0	0.01
Patient (9)	1.3	1.3	±	0.003	−0.8	0.06	1.3	±	0.003	1.5	0.07
Patient (10)	0.9	0.9	±	0.004	3.3	0.10	1.0	±	0.004	−5.6	0.09
Patient (11)	2.7	2.7	±	0.002	−0.7	0.03	2.6	±	0.002	3.3	0.03

CL, Confidence limits; S, standard deviation; n, number of assay.

The tabulated value of t is 4.303 at CL 95%.

^a: average value = (X1+X2+X3)/3.