we had similar problems with urea solutions in water. During the drying
process the concentrated ureasolution tents to creep up the walls of the
tin cup (5x12mm). We solved the problem by using precombusted quarzfiber
filter pieces (Typ MK360 cut into 5x5mm) on the bottom of the cups to give
the ureacrystals a medium to attach during the drying procedure. Such
filtermaterial can be combusted at 900 C and did not due a measureable
change to the blank value of the cups. Perhaps such technique would work
with your sample solution as well if the volume of the solvent is smal
enough to be sucked up by the fiber material.
Regards,
Klaus-Uwe Richter

email: [log in to unmask]
Alfred-Wegener-Institut fuer Polar und Meeresforschung
Am Handelshafen 12
27570 Bremerhaven
Germany