Where and what grade of Celite/DE do you guys use?

Need to order some tomorrow, not sure what to get. I don’t wanna get silicosis lol. Want good Celite. I know normal food grade will not filter well.

celite is specific product or at least a specific brand name. it is the brand name for diatomaceous earth which will work as a filter if ur using pressure or vacuum. people use it all the time in homebrewing as a filter media. im not saying its as good as celite but would work


This is from my order history on Amazon. It is not available currently but if you look at the bottom of the page it is available but in a 1000g size instead of 500g. A 1000 grams is a LOT of very high quality Celite (lab grade and safe) for under $65. I have plenty left of my 500 g container and have run many DCVC columns using it.

I get nearly all my stuff from Amazon.



Could I use Celite 545 to help filter tiny particulates in my CLS n-butane system? Maybe make a pre-coat on my 10u stainless filter then load the column up as I usually would with frozen material.


I wouldn’t put it in a loop, the way it works is you make a slurry with solvent and load on top of a already wetted and mounted filter paper. Small fines of Celite 545 could get into your extract. Diatomaceous earth is very bad to inhale to say the least.


yea if you get diatomaceous earth you should def test how much fines it has by running clean water or alcohol through it first and if it has alot of fine then you gotta wash it till it doesnt. It’s a similar problem when using it for alcoholic drinks but if you prep ur d.e. filter then none will make it past the filter.


What solvent would you use to make a slurry to load a cls column? It cannot be used dry, it would channel around be eroded by the flow of butane.


u might be able to do it dry if u loaded it with some help. if you press it down with a something u could get a pretty pack. you prob wouldnt be able to use a glass column tho which means u can really see what ur doing. In my research ive seen chromatography companies that sell “column packers” which were just something to press it down very reliably.

I think the health risk of particles going around the filter would be high. Not to mention flow rates would be very slow.


doesn’t sound fun… How am I supposed to use it for my chromatography if the particles are like smaller than 20u?

u wash hundreds of volumes of water thru them till there arent any that size left. this is common to get rid of “fines” of many things, molecular sieves is another one that u need to do this with.

yea the filter rate would be terrible without the help of a pressure differential

My extractors use nitrogen assist, I usually inject around 50 psi into a -29hg spool. With extremely cold solvent -70c I have had slow injections through filter stacks that were high micron. I don’t think it would flow very well with de.

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if u added co2 to ur solvent it would decrease viscosity making filtration go faster, especially if ur already doing it at very low temps and at pressure

We experimented with co2 instead of nitrogen. We got bad results. We ended up with liquid Co2 forming in the cold tanks -80c. We would bleed off the Nirogen pressure when the tanks were cold so the butane would remain liquid. After warming up they would build lots of pressure. More than the butaine alone could generate. It seems like it formed liquid/ or it dissolved into the butane. The extractions looked normal. Pressures didn’t jive with me so I went back to nitrogen.

yea co2 dissolves in cold polar solvents. was there any other issue besides the pressure? ru talking about in-line filtration with butane or winterization in ethanol?

I was using it as an assist gas in a closed loop extractor in place of nitrogen.

Celite works fine in chromatography to dry load your compound. This is done on top of the silica gel or whatever you are using for the stationary phase. Nothing that is undisolved in solvent will pass through and out the glass frit in most cases.

If you run a high ratio of methanol (over ten percent or so) and use silica gel you will end up with some of those gel beads in your extract lolz but you never need methanol over silica for the cannabinoids. They will come through fine at 15-25% ethyl acetate/hexane ratio. I add methanol to ethyl acetate to clean the column of the really polar stuff that ethyl acetate alone can’t even pull through silica but this all gets tossed. Over 10% methanol and I begin to see silica beads show up in the evaporated solvent that elutes but this is a pretty well known phenomena and since it gets tossed so what? I avoid using over 10% methanol because it can swell the silica gel until it cracks and channels and this will render the column useless.

Here is a shot of my LC rig after this months run. You can see the Celite sandwiched between some aluminum oxide sand and the silica gel. For the run I dissolved the compound in hexane then soaked up the hexane with Celite. Then I evaporated the hexane until dry. The compound then gets loaded dry onto the column. This keeps things uniform and uniformity is everything for a good LC seperation.

Note: there is a technical flaw in my column picture. Normally at the bottom of the sep funnel I would place a layer of normal sand on top of the frit. The diameter narrows on the column just before the frit and sand should have been used to fill this area up so the silica gel column as a whole is one single diameter. I was out of sand and it is a small technical matter. Alumina won’t work there for this because it has resolving power too just like the gel. I was lazy and didn’t go get sand and this is a technical error.

I will end up wet loading this column likely one more time on rough crude, then dump it and repack with fresh.


545 should be available at Grainger. The VO version is not, if I remember correctly.

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How do you remove the stationary phase when it is crude oil and celite mixed? Does it even come out of the rotary flask? Or do you have to use a cylindrical vessel with open top to evaporate the solvent from?

Dry loading always seemed interesting to me but how the hell do you dry load something as sticky and dry as hash oil mixed with DE?