Hello,
we want to extract benzo[a]pyrene and his metabolites from culture supernatants (containing Fetal Calf Serum) for subsequent characterization by reverse phase HPLC.
The solid phase extraction procedure could be on-line or off-line.
I would appreciate if I could get some tips on matrix choices for this application and any sample pretreatment which would allow high and reproducible extraction yields. What about protein
removal prior to extraction? Necessary, recommended or are there solutions to get around it?
Thank you for any feed-back and suggestions.

Fred

I recommend that you look at the standard methods for Oasis SPE at the Waters webside.
Let us do an off-line SPE to show how it works. The culture supernatant can be loaded directly onto the SPE cartridge. Next polar compounds including salts are washed out with water or acidified water. Next you can wash with a reasonably high organic content to remove junk. If you have standards for your metabolites, you can test at which point organic concentration they start to elute. You stay just under this concetration for your wash. Next you elute the metabolites and the benzo[a]pyrene with an organic solvent, preferentially THF. More sophisticated washes are possible as well, but I would start here to see if this is good enough.