question about buchner funnel filters

Hello everyone,

I am trying to get some information on the Buchner funnels, the ones that use the paper filters.
What I need to know is whether the filters are fine for filtering Test E. etc

Here is one of those filters at Amazon:

Amazon.com: SEOH Filtration Kit 1000ML with 90MM Funnel and Hand Pump: Industrial & Scientific

Thanks ya'll

what you should be asking is what size filter do i need to filter out any possible bacteria.

by the way most use a .22 size filter a .45 is going to be better as it is a smaller pore

ok i just APPROVED THIS POST TO, IT WAS NOT VISIBLE UNTIL NOW, IM GONNA HAVE TO SEE IF I CANT FIX IT SO ALL UR POSTS DONT NEED APPROVING

thats for people who cook up their there stuff rite?

Presser said:

ok i just APPROVED THIS POST TO, IT WAS NOT VISIBLE UNTIL NOW, IM GONNA HAVE TO SEE IF I CANT FIX IT SO ALL UR POSTS DONT NEED APPROVING

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Yeah, it's the proxy I use. Going to be posting outside of proxy going forward to avoid this. Thanks again

csuperman said:

what you should be asking is what size filter do i need to filter out any possible bacteria.

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I totally agree with you. I tried looking for a pore size on the box but there is nothing there. All it says is: Qualitative filter, 101 Fast, Retention: Coarse, Gelatinous, Precipitales.

You need quantitative .22. Do you know how long it took me to find answers to this question? I still don't know for sure. I did weeks and weeks of research. No one talks about pure sterile filters for buchner funnels. You can use the cheap ones to filter eq. But powders.... you need better. The filters that come with that system are not good enough. The filters you need cost like 2 to 3 times the cost for the pump, funnel, flask.

raysd21 said:

You need quantitative .22. Do you know how long it took me to find answers to this question? I still don't know for sure. I did weeks and weeks of research. No one talks about pure sterile filters for buchner funnels. You can use the cheap ones to filter eq. But powders.... you need better. The filters that come with that system are not good enough. The filters you need cost like 2 to 3 times the cost for the pump, funnel, flask.

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I hate to say it but I think you are right. I did quite a bit of searching and found some Millipore filters with the same diameter at .45 or .2 microns but they are in the $300.00 range, yikes.

This is something I found this morning and it may work. Not sure.
MSI® PES Membrane Filters in Filtration - Membrane Filters, GE Polyethersulfone

I actually used the filters that came with the system to filter some test acetate. It just didn't come out clear. The eq was perfect. The test acetate had like a milky quality to it. Eventually it just settled to the bottom. I'm waiting for an order of better filters to refilter it.

I hear you. The only way I would use the filters that came with the unit would be do to some kind of pre-filtering.
Those Millipore you ordered should do the trick for sure and that is actually a good price.
Come to think of it, they really are not that expensive when compared to the disposable ones.
Disposable tops cost 7.95 each or 72.50 for 12 so buying about 50 would come out to more than the Millipores you ordered.

Please keep us posted on the results once you get a chance to use the new filters.

Thanks dude

I can't even figure out what these filters are made of that came with the system. So I don't know if they are compatible with solvents such as ba or bb. Moreso ba.

To th OP, the paper filters arent going to be sterile and most buchner flask filters would house a 9cm diameter round piece of filter paper. Use this as a prefilter. I tried figuring out what would be equal to a 0.8 micron or less pore size and got tired of looking. Just get some filter papers and stack 2-3 together after wetting them with whatever you are filtering. It will get out some of the larger particulate matter and make the most of whatever filter medium you are choosing. A vaccum pump can be had on ebay for $80-the same one on a research site that sells for over $250.00.

raysd21 said:

I actually used the filters that came with the system to filter some test acetate. It just didn't come out clear. The eq was perfect. The test acetate had like a milky quality to it. Eventually it just settled to the bottom. I'm waiting for an order of better filters to refilter it. I went with these. Millipore Express PLUS Membrane, polyethersulfone, Hydrophilic, 0.22

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PES filters have the least resistance to chemicals. I'd always use PVDF or Nylon as a 2nd choice. Test acetate is not the same as making even tren acetate-it can crash a day or 2 later and especially if left in cold.

PES filters have the least resistance to chemicals. I'd always use PVDF or Nylon as a 2nd choice. Test acetate is not the same as making even tren acetate-it can crash a day or 2 later and especially if left in cold.

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You're right. They don't ship to residences anyway so had to go another route.

I use PTFE .22 at funnel.

Just go with a whatman zap cap CR and use a 70mm prefilter paper for anything. Works fine, very well actually. Supposedly they were discontinued but they are still widely available, I'm assuming stock already made, but if you actually get a medical laboratory vacuum pump you can try a fast cap which I believe filters at 15 liters per hour and you can get those as a .1.

.45 will only block passing bacteria, there is no known bacteria smaller than ,45 microns.

.22 will stop viruses as well, all know viruses and bacteria are larger than .22 microns.

.1, this will stop everything down to microbes. Which you can get this size as a fast cap, a medical laboratory pump doesn't have to cost a million dollars, they are oil less and will have and in and out port, most remind me of old computer towers, it has an on and off switch, they are quiet, and you can adjust the vacuum pressure. The good thing about a zap cap is you really can get it to pull 27hg with no problem, and I. Any remember the max pressure rating on a fastcap as they are new to me. But also pay close attention to the max temperature rating for any brand of filter you decide to choose. You can possibly melt parts of the filter paper if just a little to hot and most times wouldn't see it, but it will be painful and I imagine not good for you. And it can burn through your filter and it will just all run out.