How do I design a solid-phase extraction procedure for organic acids and inorganic anions? - WKB62922
Article number: 62922
ENVIRONMENT
- Solid-phase extraction
ANSWER
You can follow the 2x4 procedure for Oasis MAX. Inorganic salts will pass through the sorbent while the inorganic acids stick by reverse and ion exchange. A link to the complete 2x4 protocol is included below.
Load sample in 5% ammonium hydroxide.
Wash with 100% methanol or similar organic (an optional step to rid the sample of bases and neutral compounds).
Elute the organic acids with 2% formic acid in methanol (the amount of methanol used may be optimized, as well as the acid used, given the pKa values).