This example was extracted from the 1st edition of ‘Practical Handbook of Laboratory Medicine’ [16].

For example, when 0.05 mL of a 40-mg/dL spiking solution is added to 0.95 mL of serum, the added concentration of analyte is 40∙(0.05/1)=2 mg/dL.

Perform multiple measurements on each test sample (samples spiked with pure solvent, and samples spiked with spiking solution), and calculate the difference between the sample spiked with spiking solution and the sample spiked with pure solvent. In this example, the %recovery=100∙(calculated difference) / (expected difference), and the expected difference is 2 mg/dL. Then, compare the mean %recovery to the target %recovery.