Australia's Science Forum

Hi Everyone,

I just made a fresh batch of buiret reagent using 1.5g cop sulfate, 6g potassium iodide, 500ml dist water and 300ml of 10% NaOH.

It was blueish in colour and worked well (our egg whites went purple). But now Im about to put into dropper bottles etc and its already gone brown.

Did I do something wrong??

Can I recover it ?

Thanks

??? Well this is a new lone for me.. to do biuret test we just use drops of 0.25M copper sulfate and then 1M NAOH .. is the test different to the reagent?

Thanks sunray. This way worked perfect. I did get my above recipe out of the "Working in Science" book. But i will stick to your way. Much easier.