algal fatty acid extraction

[vestelshirley]

Am interested in extracting fatty acids from algae. I have a procedure for extracting from plant material, egg yolk, etc, but was wondering if there was anything algal-specific that would warrant a customized treatment.

[Bruce Hamilton]

Are you interested in the free fatty acids?, or the fatty acid profile of lipids etc. There's lots of methods for the latter, and any standard technigue that handles unsaturated acids should be OK. FFA's should also be OK, if using conventional methods, but you could check by titration as well.

Please keep having fun,

Bruce Hamilton

[vestelshirley]

The total fatty acids for a biodiesel project. Thanks for your reply.

[chromatographer1]

Pond scum to truck fuel, I LOVE IT.

You are having fun, aren't you.

I would use a cell disruptor (hearing protection required) and lots of chloroform or hexane/methylene chloride/methanol (in a hood), but please let us know how this turns out.

The project is quite interesting, and it beats the fast food deep fryer oil project ! ,but doesn't smell as good mostly likely.

best wishes,

Rod

[WK]

You are trying to produce "green" fuel from a green source!

[Bruce Hamilton]

The total fatty acids for a biodiesel project. Thanks for your reply.

Biodiesel is already extracted commercially from algae grown in sewage ponds in NZ
http://www.scoop.co.nz/stories/SC0605/S00030.htm

The easiest method would be to extract the wet macerated mass with iso-octane a couple of times, and then derivatise a few mg of the sample in the iso-octane using 2M alcoholic KOH ( 6 mins ambient temperature with plenty of vortex mixing ), then add a drop of methyl red and neutralise with 2M HCl, Inject the iso-octane phase.

The method is very dependent on the vortex mixing and cell disruption, but is quick. Bannon and Craske reported some problems, but I've always found it to be very good. Some standard biodiesel methods use other derivatising agents.

If you want free fatty acids, you could just extract with iso octane and use diazomethane ( if you're allowed ), it's very fast and easy - especially if you use a small generator, which avoids the artifact formation issues.

There are extraction systems based on chlorinated solvent extractions, and the total lipid extraction methods, eg Bligh and Dyer. The critical aspect is how much water is with your samples. If it's dried, you can also use soxhlet extractions etc..

The most important consideration is to choose a method that will be appropriate for all the lipids you're extracting in the large scale process.

Th GC methods are discussed in the various Biodiesel specifications that are freely available on the WWW.

W.W.Christie's book "lipid analysis" is always a good place to start.

Bruce Hamilton