How is a dilution factor determined?
A dilution factor is the total volume of a sample plus diluent after dilution divided by the inital volume of sample.
If you take 2 mL of a 100 mg/L original concentration sample and add 98 mL of deionized water to dilute, the dilution factor should be 50 by calculating:
Total volume ÷ Sample volume = Dilution factor
(2 mL of sample + 98 mL of deionized water) ÷ 2 mL original volume of sample = Dilution factor
100 mL of final volume ÷ 2 mL original volume of sample = 50 dilution factor.