I am called upon to analyze hops on occasion. I needed a method for determination of the volatile components in the oil. I also wanted to be able to simulate what those oil components might look like in a beer if they were exhaustively extracted. I do a serial extraction of 0.30-0.50 g of ground hops (haven't tried cones) in a plastic filtration tube (
http://www.sigmaaldrich.com/catalog/pro ... ®ion=US) that has been fitted with polyethylene frit. The procedure goes like this (all steps at RT):
1) First 5 mL shot of MeOH for 20 min. You must plug the end of the filtration tube so the MeOH doesn't run out. I stir it up occasionally with a flat-blade spatula. Push liquid out and catch it in a 250 mL volumetric flask. I have a rig where I have attached a 60 mL plastic syringe to an adapter for solid-phase extraction of large samples (red gizmo depicted here
http://www.sigmaaldrich.com/catalog/pro ... ®ion=US) to push the sample out with air.
2) Second 5 mL shot of MeOH for 40 min. Collect in same 250 mL flask.
3) Third 5 mL shot of MeOH for 60 min. Collect in same 250 mL flask.
I've used ethanol too. It is an even better solvent I just hate to waste my good clean ethanol for this analysis. I've tried this same procedure on other plant materials (orange peel, coriander, juniper berries, etc.) and it works well for all of those. Dilute the flask to volume with DI water. Makes a roughly 6% alcohol solution and removes 96+% of even the most difficult to dissolve hydrocarbon in the sample.
It's "kind and gentle" and pretty much quantitative. I analyze by headspace SPME. You can also do many in parallel. I guess you could analyze the extract without dilution. The frit is tight enough to keep the plant matter in the tube. Other solvents could be used as well. Perhaps this sort of procedure would work with methylene chloride as well. Good luck!
