[Paulska]

Hi,
I've recently started a new senior chemist position, and have inherited a PFAS analysis method from the previous chemist. I've been going through her methodology, however when I've calculated her standard dilutions, I've got completely different values and am hoping that someone could point out where I've gone wrong, or if she's miscalculated.

I have 50.0ug/mL standards of PFBA, PFOS, PFOA and a host of other standards. According to the method, the PFBA is prepared as such:

8uL of 50ug/mL is added into a 5mL volumetric flask to give you a desired concentration of 400ug/L
2uL of 50ug/mLis added into a 5mL volumetric flask to give you a desired concentration of 100ug/L

For the first, I'm getting 80ug/L and the second i'm getting 20ug/L. Is this correct? Or am I missing something?
I would appreciate any help in this!

[AWK]

8μL of 50μg/mL is added into a 5mL volumetric flask to give you a desired concentration of 400μg/L
2μL of 50μg/mL is added into a 5mL volumetric flask to give you a desired concentration of 100μg/L

If the above numbers are correct - you are right.

note - Greek letters introduced with Forum editor