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- Posts: 15
- Joined: Wed Jul 09, 2014 6:27 pm
I’m looking for some general lab technique tips on recovering the most possible mass from my fractions collected by preparative HPLC.
The solvent I’m collecting is 95:5 ethanol:water. Sample has low solubility in ethanol and is practically insoluble in water. Right now, I pool about 40mL of collected solution in 50mL plastic (PP) conical vials. I dry most of the solvent away under nitrogen blow. Next I wash with ~10mL ice cold water, centrifuge for 10 mins, collect supernatant. I add about 1mL of ice cold water again, then freeze and lyophilize.
A lot of the mass is stuck around the edges from the drying process and is difficult to collect. I painstakingly scrape away what I can and then redissolve the rest in ethanol to be added to the next run.
Just looking for any tips to improve this process. I’m thinking of centrifuging a couple times during the drying process (ex. Centrifuge at 40mL, 20 mL, 10mL solvent remaining)-- perhaps just vortexing would be enough. I’m sure there are obvious improvements I am overlooking.
Thanks!