Table 5. Matrix effects using different anticoagulants.

Anticoagulants were collected from individual donors and are not from the same source.

Concentration/Anticoagulant	EDTA	CPD	Li-Hep	Na-Hep haemolysis
QC 1, 2.97 µg/ml	1.10	1.27	1.10	1.17
QC 3, 155 µg/ml	0.93	0.96	0.90	0.91
IS for QC 1, 2 µg/ml	1.03	1.02	1.03	1.05
IS for QC 3, 2 µg/ml	1.04	1.04	1.03	1.05
Normalised QC1/IS	1.06	1.24	1.07	1.12
Normalised QC3/IS	0.89	0.92	0.88	0.87

Hep, Heparin; QC, Quality Control; IS, internal standard. Values less than 0.85 or higher than 1.15 would imply a matrix effect.