The not so ordinary properties of phosphate buffer
Part of an extraction procedure that's employed requires phosphate buffer as the solvent for one of the steps (extraction procedure is confidential). Now, I never had problems with it before , and had been making it for several months until one day some clear crystals became prominent within the solution ; as in whole chunks of it. The crystals resemble ice and appear about a day after the phosphate buffer is prepared in a large scale V shaped container. Again, this had not occured during the first several months (~5 months).
The crystal may be a hydrate of the tribasic component, anhydrous phosphate is the white brittle substance that appears once it's solid form is placed in water, however the hydrate's solubility may be drastically altered with temperature as it is with sulfate.
Thus it may be the case that even a 1 to 2 degrees change in temperature over time would have precipitated out the hydrates.
