Old NaOH no good? (View forum version)



s_laub

Posted 11 September 2009 - 09:26 AM

Hi

I recently made a solution of EDTA with some NaOH that was fairly old (I'm not sure how old, probably a couple of months) and it took a long time to dissolve the EDTA. Is this the only concern with using it on EDTA (that it might take a while to dissolve the stuff), or are there now chemical species present (due to the NaOH degraded - or whatever happens to make it "bad" over time) that have contaminated the EDTA and will inhibit downstream applications (like in a miniprep)?

THanks

Gerard

Posted 11 September 2009 - 10:10 AM

A couple of months old, I used NaOH that was a couple of years old and had no ploblems.
Just the container was firmly closed to keep the CO2 out.
You could use it without any problems if there is no more then time involved.

s_laub

Posted 11 September 2009 - 10:23 PM

THanks for the reply. So NaOH will keep so long as it doesn't react with CO2? And if it does react with CO2, it makes Na2CO3, and might this have an effect on downstream applications, or should my EDTA be just fine?

Gerard

Posted 12 September 2009 - 03:26 AM

I would use it without any hesitation. :rolleyes:

GeorgeWolff

Posted 13 September 2009 - 04:37 PM

Was it EDTA per se (as in the acid) or a sodium salt of EDTA (Na2 or Na4)?