[superg]

hi,

i've found some canula in the lab ,but they are blocked... does anyone know some tricks to unbloc them?

cheers

[stewie griffin]

You can sonicate it overnight. That's usually pretty good at breaking up nasty stuff. You could also try soaking it in a base bath overnight. A dilute acid bath could help, BUT realize that acids react with metals so you can't leave it in there forever. I would try those in that order.

[Lv2sfo]

take a flame to it (carefully), from one end to the other
then rinse with solvent

[Markov]

Metallic cannulas are notoriusly getting blocked.

As an alternative, I reccomend experimenting with different types of teflon tubing (eg used for various HPLC applications). They are available in many different diameters.
HPLC technicians also have a special knife to cut them up nicely. You want to cut them so you get kind of a sharp end.
You can pierce through a rubber septum if you pre-pierce with a needle.

Good luck,
/Markov

[superg]

hi,

thanks for reply, but nothing seems to work for unblocking this canula...i'm going for ptfe tubing: is it safe? i mean is it like polyethylene syringe, were there is always a bit of grease in?

bye

GG