People talk about filter needles in some of the posts, and they talk about filtering gear that comes in sachets. What is a filter needle and where can I get some? Are there any other ways of filtering something?
3c1ipse
Filter needles are just needles with a small build in syringe in the base. The filters contained are usually not rated high enough (smaller holes, better filtration) for the purposes of filtering injectables. However, Millipore makes a SteriVex PVDF Filter Unit at .22 ?m. It’s supposed to be good, but I haven’t given it a try.
Syringe filters are filtering units that you attach to the syringe between the tube and the needle. These are cheaper than the above mentioned filters and can be replaced when clogged up. They also readily come in .22?m and .45?m, both of which are good for our purposes. These filters are usually good for 20-40ml of oil-based gear depending on how clean it is to start with.
Then there is the vacuum filtration system. Instead of applying pressure to the syringe tube and forcing it through a filter, the vacuum filter pulls air out of the other side of the filter/container and pulls the liquid through the filter. These systems have more parts, require a pump, and are much more expensive to invest in. However, they are good for making large amounts of gear, as in 500-1000ml.
Filters that are attached to the end of your syringe can cost anywhere from $1 to $4 depending on your supplier.
If you google syringe filter, im sure you will get enough links.
I believe purchasing lab supplies is legal in most countries as well.
it is a pain in the ass to use the small .22 micron syringe filters with a syringe. i remember filtering npp a few years ago this way, never again. i would waste a whole bottle top filter for 10mL after that episode.
[quote]ubl0 wrote:
it is a pain in the ass to use the small .22 micron syringe filters with a syringe. i remember filtering npp a few years ago this way, never again. i would waste a whole bottle top filter for 10mL after that episode.[/quote]
Here is a tip.
The larger the volume of the syringe, less amount of pressure is generated for filtering.
If your going to “manual” filter your gear here are some tips.
Microwave it for 10-20 seconds before filtering, this will make the oil lighter.
Use 5ml syringes to filter through. Yes, you will have to refill more, but your fingers will thank you after a while.
Ask anyone whos tried filtering through a 25 or 20ml syringe its not easy.
If your filtering a large volume of oil, go buy a nice caulking gun. With a little modification you can use it to apply pressure to the syringe.
[quote]maxx power wrote:
ubl0 wrote:
it is a pain in the ass to use the small .22 micron syringe filters with a syringe. i remember filtering npp a few years ago this way, never again. i would waste a whole bottle top filter for 10mL after that episode.
Here is a tip.
The larger the volume of the syringe, less amount of pressure is generated for filtering.
If your going to “manual” filter your gear here are some tips.
Microwave it for 10-20 seconds before filtering, this will make the oil lighter.
Use 5ml syringes to filter through. Yes, you will have to refill more, but your fingers will thank you after a while.
Ask anyone whos tried filtering through a 25 or 20ml syringe its not easy.
If your filtering a large volume of oil, go buy a nice caulking gun. With a little modification you can use it to apply pressure to the syringe.[/quote]
Or use a 60cc Syringe mounted in a caulking gun. . . that’s my personal favourite.
If I fill only half of the syringe with oil and the other half with air I can pump the pressure up a bit and let the pneumatic effect of the compressed air push the oil through for me. Works like a charm and doesn’t require any significant effort.
STU
So when you guys filter…are you sucking the gear through the needle and filter into the syringe, or are you pushing the gear throught the syringe throught the filter throught the needle into a sterile vial or something?
3c1ipse
the latter
Just clarifying, thanks.
3c1ipse
One more thing, dont filter through 18g pinz, they are too thick and can contaminate the vial with plastic pieces from the cap.
User 20g or higher.