Chemical Forums
Chemistry Forums for Students => Analytical Chemistry Forum => Topic started by: Babcock_Hall on May 13, 2016, 03:52:15 PM
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We have had more trouble filtering HPLC solvents this past year than in previous years. If my impression is accurate, it seems to take much longer than it used to, sometimes a couple of hour to do 2-3 liters. Does anyone have a suggestion for how to minimize the possibility of getting an airlock? I am not sure that this is our problem, but I am searching around for answers.
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Well, you may simply have a bad batch of filters and/or dirty reagents. Its unlikely, but still, you have to wonder sometimes.
Is your vacuum source still at its best?
When you transfer the eluent, is the filter now covered with air bubbles? Because the liquid can't get under them, and that's surface area that's not available.
I have taken more than a few hours to filter eleunt, but that's when I was using a filter rig, meant for 500 ml, to filter 2 liters. So maybe just buy a bigger vacuum rig.
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Thank you. I will try to observe the next time we have solvent to filter. I was unaware that larger sizes were available. Does a larger rig entail using filters that are larger than 47 mm?
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There 47 mm is something of a standard size. But there are disposable filtration rigs that are easily twice the surface area.