We are trying to crystallize calcium oxalate monohydrate(COM) from a solution of NaCl in water with the procedure mentioned in the paper (Farmanesh, S. et al. Specificity of growth inhibitors and their cooperative effects in calcium oxalate monohydrate crystallization. J. Am. Chem. Soc. 136, 367–376 (2014).)
The procedure requires us to add sodium oxalate to a solution of Calcium chloride and Sodium chloride drop-wise and then allowing the solution to be left at 60 degrees for three days. We have followed the exact procedure as mentioned in the paper, but we see that in our samples the mother liquor is lost. On heating the sample in the oven for three days at 60 degrees, we had the COM crystals, but along with it we also have a lot of NaCl that has precipitated. The crystallization was performed in a beaker with a glass slide inside it, where it was covered with an aluminium foil in which holes were punched (as seen in the picture).
We are looking to use a conical flask for crystallization this time round, to reduce the loss of the mother liquor. Is there any other suggestion that we could follow?
Normally, NaCl crystallizes by slow evaporation process since solubility of NaCl is low. In your growth process, calcium oxalate monohydrate(COM) crystallizes from a solution of NaCl in water. I think below 60 degree viz. 50 C or 45 C may give better crystallization if you use constant temperature bath and hence mother liquor will not lost quickly. My suggestion is that slow evaporation or natural evaporation technique can also be applied for the given compound without using constant temperature bath. Reasonable good size crystal is possible to grow by natural evaporation technique.
Dr. Jiban Podder thanks for your reply. So you suggest for the cases where the solvent is water, its better to use a water bath for crystallization?
Did you try to cover the becker, to avoid /reduce theevaporation? If your oven has forced circulation it also helps the evaporation.
Use of constant temperature water bath always good to maintain homogeneous temperature medium in both inside and outside the mother solution. Keep the saturated mother solution at an appropriate temperature in a water bath and after a few days of solvent evaporation, embryos will join together and the crystal grows.
SILAS DERENZO We did cover our sample holder. We choose to use scintillation vials, but do not see the size of a single crystal.
Do the solubility study before growing the crystal. May I know you email id? So that I can share some papers.