Lab vacuum options:
1) Water aspirator. As noted, these consume water; the water is often contaminated with the solvent.
2) Aspirator pumps.
3) Mechanical vacuum pump. Unless liquid nitrogen traps are used (and the user rigorously maintains the LN2 level), solvent will get into the pump and either be discharged into the air or caught in pump oil. A U Texas lab was gutted years ago when someone didn’t keep the LN2 topped off on their trap. A pyrophor transferred from the pump to the oil to the air and caught fire.
Of these, the best for undergrad org labs are the aspirator pumps.
In regards to the original post – tygon tubing turns yellow/brown rather quickly due to loss of the plasticizer in the tubing material.
Subject: Re: [
This is a good question,
one I have been thinking about for quite some time in our situation here.
One question I would like to add/ask.
If you do use a water circulator, can you give me an item number or just the name of the device you use (so that I can search for it)??? I don't know what to look for, as I don't know what they are called.
On 12/4/2012 10:09 AM, Robin M. Izzo wrote:
1 – We no longer allow water aspirators.
2 – Not allowed.
3 – House vacuum or diaphragm pumps
We purchased diaphragm pumps to replace water aspirators as a sustainability measure.
Robin M. Izzo, M.S.
Get your facts first, then you can distort them as you please.
~ Mark Twain
I can only answer question number one: I have worked in pharma and in manufacturing chemistry QA and R&
Dlabs over the past decade and have NEVER used a sink aspirator for filtering powders. We always had a house vacuum or vacuum pump set-up for filtering. I finished grad school four years ago and we never used a sink aspirator for filtering in my research lab. We very rarely used them in the teaching labs. I think both my graduate and undergraduate institutions are moving away from sink aspirators for a number of reasons: the waste issue you mention here, the potential for sink overflows, the ridiculous waste of water, and even the noise level when lots of students are using them in a large teaching lab.
I also agree with someone else’s comment about Fisher or VWR. If a google search doesn’t turn up what I want right away, I usually call our Fisher rep and let him do the leg work for me. He’s never let me down.
Good luck, and do let us know if you come up with an effective response to the but-we’ve-always-done-it-that-way Ph
Katherine C. House, CCHO
Chemical Hygiene Officer
Cormetech Environmental Technologies, Inc.
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[mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Kim Auletta DCHAS-L Discussion List
December 04, 2012 8:27 AM
] water aspirator - vacuum question DCHAS-L
I need the expert opinion of chemists working with 21st century ideas!
I was in a lab yesterday in Chemistry that is run by a PI older than the hills. His lab is filtering powders and solvents using the sink aspirator. All of the tygon tubing (both sides of vacuum & flasks) is discolored and shows signs of deterioration. They say this tubing is only looking that way because its really old. There was a flask for trap set up between the sample & the sink. I tried to explain that this set up may be allowing solvents to go into the water & down the drain. They tried in their best "I'm the seasoned Ph
DChemist and you're not" voices to tell me it was ok and that there was no other way to do this and that everyone, including in industry, does it this way. Really?
So - my questions to all of you enlightened chemists:
Do you still use the sink aspirator/vacuum?
2. If so, what kind of trap do you use to prevent solvent or other hazardous material (liquid & vapor) from going down the drain?
3. If you no longer use this filter/vacuum set up, what do you use?
thanks for your help!
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