Page 2 of 2

Posted: Fri Dec 05, 2008 8:54 am
by DM909
Hello, I do not know how regulated your standard is, and how much freedom you have to change things. If you are R&D and the one creating the standard you could have the option to prepare the hydrate and avoid hygroscopicity problems. Of course this depends on the nature of the material.

We have had one case where the standard we were creating was hygroscopic and we were of course experiencing your same problems. We opted to prepare the monohydrate instead and this was not hygroscopic.

Posted: Fri Dec 05, 2008 9:18 am
by HW Mueller
syx, this is indirectly related: In keeping oxygen away from samples a glovebag was as good or better than a glovebox. I have had much more problems keeping O2 out of samples than H2O.

Posted: Fri Dec 05, 2008 9:35 am
by syx
some substances, eg citicoline sodium, do not have hydrate form. they could absorb the water until they are very wet.

mr Mueller, what if we fill the box using inert dry gas? could we reduce the O2 content inside it?

Posted: Fri Dec 05, 2008 4:32 pm
by HW Mueller
That was the main advantage of the glovebox, one can change the atmosphere relatively fast: Press it down to expell almost all of the air, then blow in your gas.