Ever wonder if there was an easier way to filter solutions besides turning your hands into nearly useless pulp filtering through our beloved Whatmans, or want to use a .22um filter for safety's sake, but know the effort exerted is just not worth it? Then check these new filters out.
Did a test with a Whatman .45um and a Millipore hi-cap .45um and .22um, using sesame oil; both filters utilize PVDF filtering media, sesame was normal USP grade unfiltered, at room temperature (60F; not warmed). I had no way to regulate hand pressure on the syringe to force oil through test filters, but tried to be as consistant as possible. I tried the Whatman first, then the hi-cap .45um, followed by the hi-cap .22um (by which time my hand was worn out; I'm sure I wasn't pushing as hard on #3).
Using a 30ml syringe (which applies moderate PSI pressure), here are my filtering times:
#1) Whatman .45um 25mm filter, 30ml oil: 5 minutes, 15 seconds
#2) Hi-cap .45um 10cm2 filter, 30ml oil: 1 minute, 15 seconds
#3) Hi-cap .22um 10cm2 filter, 30ml oil: 5 minutes, 30 seconds
Like I said, by the time I got to filter #3, my hand wasn't applying quite as much pressure as it was when I started.
My next test will be a structural integrity test to determine if hi-cap filters can hold up to the pressures we are applying to the Whatmans; the pressures suggested are 45PSI, which can be exceeded by a small syringe. The filter media itself seems to hold up well to use, and the clear housing lets you see the entire surface area of the filter. Overall, the hi-cap .45um's seem to be an excellent choice for pre-filtering your product, then it can be run through the finer .22um filter. Stay tuned for more info
Oh, and yes, I do carry them; not very economical, but it has to do with the packaging; prices should drop soon. See thread
www.xtrememass.com/forum/showthread.php?t=1884 for pricing and pics.
02-26-2004, 12:09 AM
Linear Mode
