[eukaryote]

Hey guys, i'm trying to create a standard curve as a way of measuring the pureness of antabuse. So far I have used copper(2) complex and antabuse in 80% ethanol without much success. I get a curve, but the absorbance changes in a negative matter over time, any suggestions on how I could come around this issue? 

[Arkcon]

Hey guys, i'm trying to create a standard curve as a way of measuring the pureness of antabuse.

Great.  Why not show us the curve you have.

So far I have used copper(2) complex and antabuse in 80% ethanol without much success.

You shouldn't say a protocol doesn't give much success, if the only thing wrong is a poor curve.  Or do you mean it doesn't work?  And exactly why not?

I get a curve,

Great.

but the absorbance changes in a negative matter over time,

Bummer.  Are you sure that's not supposed to happen?  Will is slow down if you wait a while?  Will absorbance be gone completely if you wait too long?  Then work faster.  Or figure out how fast you can perform all tasks, add a minute, and make sure every reading waits exactly that long.

any suggestions on how I could come around this issue?

Try anything.  Try everything.  Or give up.  There's always options.