Spike Recovery Calculator

Spike Recovery Calculator: calculate recovery % with consistent units and explicit assumptions.

Inputs

Recovery basis

Original sample amount

Final preparation amount

Native concentration

mg/L

Spiked measured concentration

mg/L

Spike stock concentration

mg/L

Spike amount

Recovery % = 100 × (measured analyte mass − native analyte mass)/added spike analyte mass

Solid sample: mg = extract mg/L × extract mL /1000; native mg = mg/kg × sample g /1000

Use actual final preparation amount and matching analyte reporting bases. Recovery is not clamped; method-specific acceptance criteria apply.
Solid mode uses the final measured extract, known dry sample mass and liquid spike; concentrations must already include any extra instrumental dilution correction.
Reference: EPA matrix spike equations https://www.epa.gov/sites/default/files/2017-04/documents/equations_utilized_in_conjunction_with_ism02_4_04132017_508.pdf

For the example inputs: Spike recovery = 100 %.

Recovery % = 100 × (measured analyte mass − native analyte mass)/added spike analyte mass