Analytical Spike Addition Calculator
Analytical Spike Addition Calculator: calculate direct addition: vspike with consistent units and explicit assumptions.
Inputs
mL
mg/L
mg/L
mg/L
Results
- Spike volume
- 2.061856 mL
- Final concentration
- 30 mg/L
- Final volume
- 102.061856 mL
- Solvent volume
- 0 mL
Formula
Direct addition: Vspike = increment × Vsample / (Cstock−Cnative−increment)
Made-to-mark: Vspike = increment × Vfinal / Cstock
Assumptions & limits
- Increment in direct mode is above original native concentration; made-to-mark mode is added-analyte concentration in final preparation.
- Direct mode assumes additive small spike volume; made-to-mark mode uses measured final volume.
Worked example
For the example inputs: Spike volume = 2.061856 mL; Final concentration = 30 mg/L; Final volume = 102.0619 mL.
Direct addition: Vspike = increment × Vsample / (Cstock−Cnative−increment)