Australia's Science Forum

Okay, don't ask me how it happened, but it appears that there is a piece of polystyrene stuck in the tip of a burette! Any suggestions how to remove it? I know that acetone will dissolve polystyrene, but I certainly don't want to run that through the burette.

Try strong Acid hcl might work

Have you tried sticking a fine piece of wire up the end?

I find a fine piece of fuse wire often helps:)

I tried the piece of wire, but found it is not polystyrene but something more solid and the wire won't penetrate it. I'm trying to soak it but because it is blocked, I can't get liquid to flow through. Currently I have it just standing in some water, see what happens.

Do you use NaOH in your burettes? If so its probably that salt build up you get when NaOH is in glass. What about warm to hot water and soak?

That's what I was thinking Rae. It's the first time since I've been here that we have used all the burettes we have, so I don't know how long it has been sitting there nor what has been used in it.

I used a piece of fishing twine in mine, i thought I was the ants pants LOL

Very fine, and didn't break the tip...unlike the probe i used last year - that wasnt fine enough...whoops!

I do flush mine out with hot water after each use and before I store them. I've touch wood never had a problem.

Backwash the burette -
Turn it upside down, point the end into a bucket or similar,put tubing on the tap so you can cause a high pressure jet of water to go through the tip.. and it often will flush the obstruction away.
Use for pipettes also
If it doesn't - then = throw the burette out.
I know that sounds wasteful, but think about how much time you are spending on it and how much that equates to in your wage dollar terms , and often a new piece of equipment is the most efficient use of the money.
I don't use hot water, ever, in burettes or pipettes.. maybe because I worked in Research for many years with A grade glassware - in case it causes distortions in the glass and hence the markings.

(Now I'm in the right post )

Success! Soaked the tip in water overnight and it is now running fine. Simple!

My GA made me a plastic pipe holder for mine using plastic down pipe on a wooden base with handles and with tiny holes around the bottem of the pipe to let the water out and air in.
I wash them and open the valve and put them in the pipe upside down till they are dry works every time.

We have a piece of 300mm diameter poly (length approx 100mm longer than burettes) with poly stopper attached at one end to act as base. It can be left in the deep sink or in a bucket to soak or rinse burettes if necessary.