PLEASE HELP!

I need to get silica gel for column chromatography. I need about 100 grams of Merck Silica Gel 60 (15–40 µm) or equivalent.

I’ve been searching the web for hours and hours and can’t find a single place that sells column chromatography silica gel to the general public. I keep finding places that sell in bulk only, or they sell general purpose desiccant silica gel with no specs (I can’t use that).

Are there any such places anywhere that sell to the general public?

a quick search gave me this

i dunno, it's worth a shot

found it with this search string

I'll check them out. Thanks.

SWIM has already ordered a special vacuum liquid chromatography column. He’s researched various different types of liquid chromatography techniques and thinks vacuum liquid chromatography looks like the best way to go. For that, special silica is used (60, 15-40 um) which is hard to find. However, the column he order will also work for flash chromatography, so he can do flash chromatography (with vacuum instead of pressure) with easier to find flash grade silica as a backup plan if he can’t get the special silica. Flash chromatography seems less convenient because you need to keep the silica immersed in solvent at all times. And it’s said to take longer than vacuum liquid chromatography.

really (?)

was under the impression prep liquid chrom would work well too, albeit a bit costly ($$). though considering the complexity and various packing considerations, perhaps vacuum liq chrom would be less of a hassle

I didn't look into preparative liquid chromatography. I didn't run across that much in my research.

Why would think that's the better way? I don't care too much about cost of materials.

prep LC is often used in the pharm industry to separate unreacted intermediates from final products. it's also used in biotech to purify proteins.
just seemed logical, I guess.
(Reborn oughtta chime in on this, he should know a thing or two about separation science)

Hey Guys.
Yea sorry I have been out for a while, home computer took a dive.
All better now.

69ron your not specific enough in what your trying to accomplish for me to help at this point.
As far as chromatography goes there are many different ways to solve a problem but depends on what your doing. Hell for lots of stuff just simple off line solid phase extractions with cartridges can massively enrich and clean up a sample. Its the cheapest and easiest form of chromatography out there.

PM me 69ron I can probably help you out, have tons of old not used packing materials around.

The analytical world has moved entirly to high pressure LC (HPLC), often with nano columns, so many of the old ways have become obsolite. That said prep chromatography still uses many older methods and packing materials.

Sorry for spelling still dont have word installed

The silica always needs to be immersed in solvent once one starts a column. Once the silica dries out during a column problems start. The problem with flash chromatography is one needs a pump and tubing that can handle organic solvents.

SWIM also has experience with chromatography so if SWIY needs advice please ask.

Preparative liquid chromatography if benzyme meant preperative HPLC is extremely expensive btw don't even consider if unless you have 50,000 bucks to spend on equipment even more in the pharmaceutical industry.

then vacuum chrom sounds like a quick/practical way to get it done.

swim is considering the Gast DOA/DOL diaphragm pumps (they are corrosion-resistant) sold on the 'bay, they've been selling for 50 - 65 USD recently, even some used ones with gauges (they can pull 25.5 inHg, continuously, or max out 60psi pressure).

swim once used them in a polymer research lab, attached to a rotavapor, and doing impromptu flash chrom separation of cis/trans 2,2,4,4-tetramethylcyclobutanediol, with 75mesh silica/montmorillonite as the stationary and chloroform as the mobile phase

^^Yea SWIM thinks adding a bit of pressure or sucking is key in getting nice quick separation during column chromatography. Of course one should have mobile phase and fraction checking techniques at hand before beginning. Seems like a nice handy little pump benzyme.

oh it is.
the lab models in particular, the others are more for industrial aps.

the former are essentially lab/med/dentist grade. corrosion-resistant, designed to run all day, every day, for a wide variety of applications including protein seps.
getting one for vacuum distillation and desiccation

SWIM has a diaphragm pump. The problem with it is that it vibrates and the vacuum is not 100% constant. It sucks, then doesn't, then sucks, then doesn't, over and over really fast. This causes a vibration and a really fast fluctuation in the vacuum. This can cause problems in some cases where you need a constant vacuum that doesn't fluctuate. For example, it can cause filter papers in a Buchner funnel to vibrate and lose a complete seal (especially when filtering acetone or DCM).

While they are great for some things, you still need a normal vacuum pump for cases where the vacuum fluctuations are not acceptable.

I think with column chromatography you’ll be fine using a diaphragm pump.

this is something inherent to diaphragm pumps. it does that with swim's current KNF pump, and did that with the Gast pump in the polymer lab (the needle bounced very quickly between 24.5 and 25.5 inHg). gotta figure, the diaphragm moves like a speaker; it has positive and negative displacement, which is why it can operate as a vacuum and pressure pump.

the continuous ones are the rotary vane pumps. they are heavy-duty, and often multi-phase. these pumps offer greater displacement. a bit overkill for filtration, but good for larger scale distillations (like use with 12L heavy-walled RBFs), or distillation of really high-boiling compounds.


for most apps, a diaphragm pump is quite adequate, and column chrom is no exception.

Hi guys

I was going to start a thread about this, but I searched and found this existing (albeit old!) thread. I decided that it is probably best to resurrect this instead of creating a new one for virtually the same question.

Incidentally, although my profile appears new, I have been reading this Forum for years I will post some introductory message about me later XD I'm sort of in a rush so...

I wanted to kindly ask people where they obtain their silica gel for column chromatography from. I use silica gel a lot, it's an awesome material for separating organic molecules...

However the chemical suppliers are charging through the roof for it. The most common grades (mesh 70 - 230 and mesh 230 - 400) are like £70.00+ per kg in the UK, and sometimes a seller may even refuse to provide this if you are not trading from a well-known company or something.

So... where can anyone get silica gel for chromatography in multi kg quantities without having to sell their mother to slavery ._.

I've been getting my Silica Gel 60 for Chromatography from this company in Vancouver, Canada. No complaints about it so far, US $30/kg and they also take orders for custom sieve sizes. Give them a shot!

http://baotou-rareearth.com/others.html#silica

Here's the quote they gave me upon my first purchase:

Product: Silica Gel 60 (specs attached)
Price: USD $30/kg
Shipping Terms: EXW Richmond, Canada
Delivery notes: In stock in Richmond, Canada. Ships 1-5 business days after payment received. Shipping method to be instructed by buyer. We can gladly arrange and calculate shipping & duty costs upon request.
Packing: Individual 500g jars packed in 5 kg boxes