Solid phase extraction (SPE)

[Sarah1233]

Hi all

Iam trying to seperate a weak acid from plasma. Does any has experience with SPE, I tried to use sep pak but it doesn't give me the required sensitivity, any suggestions.

Susan

[Vlad Orlovsky]

what is pKa of your acid? You can inject plasma directly into Primesep D mixed-mode column. Plasma proteins will repel from the stationary phase and elute close to the void and acid will retain by anion-exchange mechanism. Something like this:
http://www.sielc.com/Technology_DirectP ... lysis.html