-
- Posts: 12
- Joined: Fri May 01, 2015 4:59 pm
I have a problem with extraction of melittin - a 26 amino acid peptide from petroleum ointment.
My method:
1.~0.250 g of melittin ointment is dissolved in 2 ml of n-hexane
2. LLE is conducted - 2 ml of 25%ACN is added and solvents are stirred for 30 minutes
3. The 25%ACN layer is centrifuged
4. 100ul HPLC injection is made.
Problem: Recovery is only 80% (i need 95-105%)
I tried various concentrations of ACN and 25% ACN was, unfortunately, most effective.
I tried also Isopropanol, and methanol and they both were weaker than ACN.
I tried adding 2x 1ml of 25% ACN for 15 minutes and the recovery was the same
Any suggestions?
Cheers,
Dorian