I currently pull using a 5ml glass pipette and it works just fine but it is tedious and time consuming so I've been researching alternative means of pulling and have seen separatory funnels mentioned a few times. I am curious if anyone who does A/B extracts could help me out with a few questions I have regarding its usefulness.

My basic understanding would be that I would follow my extraction notes as I normally do using my erlenmeyer flask and mag stirrer/hotplate and when I am ready to pull I would need to filter the basic solution into the funnel to avoid getting any plant material or sludge on the walls of the funnel as well as clogging the stopcock. I would then add naphtha, mix, release pressure and let separate a few times. So because naphtha floats on top, I would need to slowly drain the basic solution out into a beaker until only my naphtha remains which would then be poured out from the stopper side into my evap dish. From here I would pour the basic solution back into the funnel for a few more pulls.

Does this sound correct?

Is it really worth the multiple transfers of basic solution? Seems like a high risk of accidental spillage...

If there is sludge/plant materiel on the walls of the funnel, what is the best way to get it off and out of the naphtha?

Sorry for so many questions, I am just trying to wrap my head around the usefulness of this glassware in regards to my extraction process and couldn't really find exact answers to my questions upon searching.

Yes this is correct.

Also don't forget to uncap the funnel before opening a stopcock otherwise the fluid will bubble and stop flowing due to underpressure (I forgot to do this many times).

Another culprit is the pressure release. Always hold the cap to avoid spillage and release often. The initial pressure buildup can be great and the release can result in spraying the bits of the content on the wall.

Other than that, using a separatory funnel is comfortable and I love it for bigger oextractions. I prefer decanting from tall beaker followed by pulling by syringe for smaller separations.

Filtering plant material before separation is important, otherwise it will easily clog the funnel (the opening is quite tight).

As for the stopcock, you can choose glass or PTFE. Most people go for PTFE as it does not require grease, but is more heat expansive and can tighten unexpectedly.

I have a 1L glass funnel with glass stopper and ground glass cap. It works amazingly though few drops of basic solution are left after separation and further got rid off by decanting.

I use graduated glass piston pipettes.
Can be bought in big sizes. Mine is 25ml. Just two pulls and you done. They work very well if you lube the top so you can pull slowly.
In my opinion cheaper and better than a sep funnel where you have to repeat the washings.

Seperatory funnel is good when you use a heavier than water solvent like DCM. So you just need to add the DCM shake/vent and then seperate it for easy pulls.
For lighter than water its not worth it draining 1l of base soup to get 50ml of naptha.

Yeah, this is what I figured, it didn't really seem worth it to me either but I figured I'd ask here to be sure.


Thank you, this is definitely what I will look into...seems a hell of a lot easier than my 5ml glass pipette. I get great results with my current method, but I am just looking into ways to make my extraction as simple as possible and right now the pulling stage is the most time consuming in regards to actual hands on work.