Calculate the percentage recovery given the following information:
Baseline sample preparation: 1.5 mL serum + 0.25 mL water
Spike sample preparation: 1.5 mL serum + 0.25 mL 5000 mg/L standard
Baseline sample measured concentration: 950 mg/L
Spiked sample measured concentration: 1621 mg/L

Question

Quizplus · Accepted Answer

To determine the concentration of the spike added:
5000 mg/L in 1.75 mL (total volume) = 2857 mg/L in 1 mL = 714 mg/L in 0.25 mL (the actual volume added.Concentration recovered = concentration measured with spike minus baseline concentration
= 1621 mg/L - 950 mg/L
= 671 mg/L
Percent recovery = concentration recovered divided by concentration added time 100%
= 671 mg/L / 714 mg/L × 100%
= 94%

Calculate the Percentage Recovery Given the Following Information