Whatman filters
- Thread starter candle25
- Start date
GIJoe
Pat Tillman, American HERO
candle25 said:
I've got about 30 .45um sterile Whatmans left; in talks w/ a mod to see how to approach selling these, among other things. E-mail me securely at [email protected] for pricing. I've got some hi-flow .22um & .45um syringe filters a mod's trying, so if they're any good, I'm sure he'll mention them.
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GIJoe
Pat Tillman, American HERO
After reading candle25's thread Invalid Link Removed I am worried about .45um not being sufficient for others to sterilize their product w/o fully removing spores. I called to place an order w/ Whatman to order as much remaining stock as I can afford on Whatman 25mm, .22um & .45um sterile filters (which has been discontinued; I will find out the true extent of this tomorrow morn, and post results). I called after hours, so I will find out tomorrow the story behind this "discontinuance".
Does anyone know what is involved in killing spores? Does gamma irradiation (the industry standard for sterilization of the filtering products we purchase)? Or are they able to "get away with it" because they assemble and sterilize in a class "X" clean room? Thanks for the input.
Does anyone know what is involved in killing spores? Does gamma irradiation (the industry standard for sterilization of the filtering products we purchase)? Or are they able to "get away with it" because they assemble and sterilize in a class "X" clean room? Thanks for the input.
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GIJoe
Pat Tillman, American HERO
jweave23 said:all I know is that these .22's better be "high flow", because using regular one's seems virtually impossible for me. When I used them my hand cramped up (from filtering) more than when I watch a Jenna Jameson flick
LMAO!! That's why I haven't carried them in the first place, but now, I'm thinking pre-filter, then .22um filter to finish up. All my hi-cap. vacuum filters are .2um PVDF for sterility reasons, and can be used w/ pre-filters for longer primary filter life. They will be tested and approved by a mod first.
Skye
Well-known member
GIJoe said:
A clean room takes care of most of it. A .22 and BA takes care of it for us. rember this is largely a game of numbers, IE the probability of getting a infection. it is never 0. Nor does any process get rid of everthing.
look here (already did the research)
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and
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GIJoe
Pat Tillman, American HERO
ManBeast said:
Unfortunately, filtering would have to be done in 2 draws; nobody makes a syringe pre-filter I can find w/ a locking luer outlet (I don't know if that would work well anyway). However, filtering would be considerably easier; if that isn't good enough, I've got vacuum filtering units tailored for this size run that eliminates the hassles of syringe filtering. Will be tested, and mods will report results.
candle25
Active member
Are you talking about those hand pump Buchner funnel type set ups? It seems like you'd lose a good bit of your gear in the funnel itself if that is what you're talking about. Plus you'd lose some more when you transfer the soln from the vacume flask to the sterile vile. I'm thinking 1-1.5 ml loss. It would be nice to have an automated system but doing it by hand isn't so hard.GIJoe said:
GIJoe
Pat Tillman, American HERO
candle25 said:
No, these are completely different (pics below)
![MB3108-06[666-EN].jpg](http://www.millipore.com/images/medium/MB3108-06[666-EN].jpg)
![872901-06[900-EN].jpg](http://www.millipore.com/images/medium/872901-06[900-EN].jpg)
![MB4159-06[678-EN].jpg](http://www.millipore.com/images/medium/MB4159-06[678-EN].jpg)
There is very little left in the filter, but just like w/ syringes you should run oil through filter to properly purge it. The first two units are .2um sterile filtering units; hook up a hand pump or vacuum unit/aspirator and there's no inconvenience of syringe cramps. Simply dump in top, attach vacuum, come back later. "Sterilized" filtered solution is deposited into the lower flask/tube. However, the steritop 500ml unit must be used w/ heavy glass lab bottles (I use Pyrex 1000ml lab glass bottles w/GL45 threads).
The 3rd pic is of the hi-cap syringe filter (not the one w/ bell housing).
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Kitchen Chemist
Active member
what kind of vacuum are you using bro to filter bro?
GIJoe
Pat Tillman, American HERO
Kitchen Chemist said:
I personally use a hospital aspirator which pulls 22"HG (200torr), but I've used it w/ a hand pump (brake bleeder pump works), takes a squeeze down every 5-10 minutes to maintain vacuum. My hi-vac pump works extremely well with this; however, I do such bulk that I have switched over to 142mm filter setup through a SS pressure vessel. The 500ml filter setup will do 1 gallon (4 liters) of raw (high-viscosity) chems before I have to change it (may need to use a space heater to keep filter & solutions warm); thinner solvents you can do more.
candle25
Active member
Ok, I just finished the transfer I had mentioned earlier. My boy SethL & I took turns pushing the gear through a 0.20um filter. It was only 50ml but it was hard as hell!!! Just wanted to let you all know. The auto idea is sounding better all the time. I found them in my Fisher catalouge today. Kinda pricy IMO.
GIJoe
Pat Tillman, American HERO
Hi-capacity syringe filter initial test results w/ sesame oil
Did a test with a Whatman .45um and a hi-cap .45um and .22um, using sesame oil; both filters utilize PVDF filtering media, sesame was normal USP grade unfiltered, at room temperature. 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. I will also test filter materials integrity to determine if failure can occur after filtering a serious amount of product. The .45um's seem to be an excellent choice for pre-filtering your product, then it can be run through the finer .22um filter.
Did a test with a Whatman .45um and a hi-cap .45um and .22um, using sesame oil; both filters utilize PVDF filtering media, sesame was normal USP grade unfiltered, at room temperature. 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. I will also test filter materials integrity to determine if failure can occur after filtering a serious amount of product. The .45um's seem to be an excellent choice for pre-filtering your product, then it can be run through the finer .22um filter.
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GIJoe
Pat Tillman, American HERO
Good and Bad news
The bad
Called Whatman today, to ask where my syringe filters were. Gave them my PO#, and needed a tracking#. Said my order was on back-order for 4-6 weeks. I said "Wait a minute; I confirmed that you had a small supply of filters in stock. I was on the phone, and you said you had my order in reserve". They went and checked. Come to find out, my distributor confirmed my order with Whatman, but didn't place the order until the next day. My Whatmans went out the day I confirmed my order, but not to me -- because my damn distributor didn't have their s*** together. There are no more Whatman 25mm sterile syringe filters for 4-6 weeks, so if you need them, buy them from your source while you can. Sorry for the confusion.
The good
I'm in talks with the manufacturer for a discount on a large quantity of hi-cap syringe filters; currently, prices are too high for these filters, so the product rep. is putting together a custom order with a quantity discount so cost is acceptable. Am anxiously awaiting results from Chemo as to his opinions on these filters.
The bad
Called Whatman today, to ask where my syringe filters were. Gave them my PO#, and needed a tracking#. Said my order was on back-order for 4-6 weeks. I said "Wait a minute; I confirmed that you had a small supply of filters in stock. I was on the phone, and you said you had my order in reserve". They went and checked. Come to find out, my distributor confirmed my order with Whatman, but didn't place the order until the next day. My Whatmans went out the day I confirmed my order, but not to me -- because my damn distributor didn't have their s*** together. There are no more Whatman 25mm sterile syringe filters for 4-6 weeks, so if you need them, buy them from your source while you can. Sorry for the confusion.
The good
I'm in talks with the manufacturer for a discount on a large quantity of hi-cap syringe filters; currently, prices are too high for these filters, so the product rep. is putting together a custom order with a quantity discount so cost is acceptable. Am anxiously awaiting results from Chemo as to his opinions on these filters.
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GIJoe
Pat Tillman, American HERO
Quote:
Originally Posted by candle25
Ok, I just finished the transfer I had mentioned earlier. My boy SethL & I took turns pushing the gear through a 0.20um filter. It was only 50ml but it was hard as hell!!! Just wanted to let you all know. The auto idea is sounding better all the time. I found them in my Fisher catalouge today. Kinda pricy IMO.
Ebay has an automated syringe dispenser/pump Invalid Link Removed; bids start at $275. Sounds expensive, but not (think hand cramps and blisters), has 5 days left.
Another one here Invalid Link Removed bids start at $200.00
Here's a cheap one ($9.00), don't know if it will work Invalid Link Removed
Here's one for $9.99 + $38S&H Invalid Link Removed
Originally Posted by candle25
Ok, I just finished the transfer I had mentioned earlier. My boy SethL & I took turns pushing the gear through a 0.20um filter. It was only 50ml but it was hard as hell!!! Just wanted to let you all know. The auto idea is sounding better all the time. I found them in my Fisher catalouge today. Kinda pricy IMO.
GIJoe said:If you're talking about an auto syringe dispenser, VERY nice, but you'll have to sell your car for that one ($1250-$2500; one can dream, though); well, not quite, but nice device nonetheless
Ebay has an automated syringe dispenser/pump Invalid Link Removed; bids start at $275. Sounds expensive, but not (think hand cramps and blisters), has 5 days left.
Another one here Invalid Link Removed bids start at $200.00
Here's a cheap one ($9.00), don't know if it will work Invalid Link Removed
Here's one for $9.99 + $38S&H Invalid Link Removed
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GIJoe
Pat Tillman, American HERO
Quote:
Originally Posted by ManBeast
Is the filtering and pre-filtering done with one push? or do you have to force it through one and then draw it up again to force it through again?
ManBeast
The luer-lock output version of the hi-cap 10cm2 syringe filters allows you to pre-filter through a .45um, then filter through a .22um -- in one draw. It still takes about the same amount of time as pushing it through a whatman .45um 25mm filter. Just lock the .45 to the syringe, then lock the .22 to the .45 luer-lock output, and finally, lock a needle to the .22 output.
Originally Posted by ManBeast
Is the filtering and pre-filtering done with one push? or do you have to force it through one and then draw it up again to force it through again?
ManBeast
GIJoe said:
The luer-lock output version of the hi-cap 10cm2 syringe filters allows you to pre-filter through a .45um, then filter through a .22um -- in one draw. It still takes about the same amount of time as pushing it through a whatman .45um 25mm filter. Just lock the .45 to the syringe, then lock the .22 to the .45 luer-lock output, and finally, lock a needle to the .22 output.
GIJoe
Pat Tillman, American HERO
GIJoe said:
Forget about the back-to-back filtration (too long, complicated, and expensive). Instead, the prefilters allow efficient use, and the .22um's do 150-200 of prefiltered fluids 3-4X faster than the whatmans.
Easiest way to filter with these and keep from blowing the membrane is suck up a little air pocket (1-2ml of air) before you filter; this will give you a buffer so that when you get pissed and "accidentally"give it that brute squeeze, the air buffer will keep you from popping the membrane. I use 10-20ml syringes now with this method and have yet to pop one.
Easiest way to remove the .2ml of fluid which can remain in the filter is to suck up 5-10ml of air and push it slowly through the filter. The filter housing is clear, and you will see EVERYTHING that was filtered out of your mix.
To sum up: 3 to 4 times faster filtering, which translates to easier and/or quicker filtering, less hand cramps, and more free time (sleep time, play time, workout time, sell time, etc.) to do things.