Hey all,

I'm doing SPE for PFAS but cannot find the right answer to calculations.

I have NIS and EIS standards for the LC TQ.

I did the following:

500 mL of water sample (weight = 485.14 gram of water)

Spiked 50 uL of 1000 ng/mL PFBA stock solution

I did SPE and reconstituted it back into 5 mL MeOH. Used 1 mL of this in my LC/TQ.

How do i calculate the recovery and how do i calculate the recovery back to my exact water sample?

I'm not good in calculations and need to learn.