Whatman filters CAN NOT be used in reverse

[SV-1]

I wanted to find out once and for all if whatman filters could be used in reverse as used in this technique.

Written by Corleone @ Elite

OK, maybe someone has thought of this before, but regardless I feel very proud and figure I should post it for those with a short temper like myself.

I don't know about the rest of you, but sometimes filtering 100ml's of fina can be very frustrating and enough to throw your bp through the roof. Nothing worse than having to exert total effort to push the oil through the **** filter to the point where sometimes you get splashback where you push too hard and oil is forced through the plunger. I HATE THAT! My fingers get red and painful from all the pressure exerted. Not to mention there's something about the stupid researchkit kits that cause the filters to clog after a crummy 10ml's.

Well I figured out that since the filters work both ways(yes you can filter reverse), that if you slide a credit card in between the plunger and finger grip to create pressure, and then duct tape the bottle to upside down position you can just sit back, relax and let gravity do it's job. It will filter itself into the syringe and you will have nice filtered fina effortless.

That's my contribution for the week

And as much as I wanted it to be true (I hate the hand cramps from filtering as much as anyone), it's not.

My email to Whatman.

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Question regarding 25mm GD/X PVDF filters

I was hoping you could tell me whether or not your 25mm GD/X PVDF filters can be used in reverse. In other words can these filters also work by creating a vacuum in the syringe and drawing the liquid in reverse through the filter into the syringe? Would the post filtered quality be the same as normal?
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Whatmans response:

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Re: Question regarding 25mm GD/X PVDF filters

Thank you for your inuquiry, which was directed to my attention.

GD/X syringe filters have a triple layer of prefilters on top of the final membrane filter.
If you were to reverse the direction of flow, the filter would not function properly, since
the prefilters would not "see" the solution before it got to the membrane. The advantage
of prefiltration would be completely lost. In addition, since the filter is not intended to
be bi-directional, the upper prefilter layers are not supported and would move out of
position, possibly obstructing flow and/or losing fibers.

The GD/X filters should NOT be used with reversed flow.

Sincerely,
Elaine Heilweil
Technical Support Mgr.
Whatman Inc., Clifton NJ
1-800-922-0361

	finastride