F
Extracted sample stability at +4 °C, 24 hr
QC level [ng/ml]	2	4	20	40
	122	112	91.0	104
93.5	106	91.8	96.1
111	94.8	98.2	93.5
98.4	97.6	91.3	89.8
% of nominal concentration	106.2	102.6	93.1	95.9
Imprecision [%CV]	12.8	7.9	3.4	6.0
Extracted sample stability at +4 °C, 48 hr
QC level [ng/ml]	2	4	20	40
	106	108	93.7	110
105	98.1	94.6	98.9
103	98.4	95.0	92.6
108	93.1	89.7	85.5
% of nominal concentration	105.5	99.4	93.3	96.8
Imprecision [%CV]	2.1	6.2	2.4	10.4
Extracted sample stability at +4 °C, 72 hr
QC level [ng/ml]	2	4	20	40
	96.5	112	96.4	104
101	95.3	103	95.2
94.2	105	93.5	99.5
100	96.9	92.6	89.3
% of nominal concentration	97.9	102.3	96.4	97.0
Imprecision [%CV]	3.1	7.7	4.7	6.3