Question
Posted on: March 6 2013In a phosphate syrup, crystallization occurs.
R/sodium Monohydrogen phosphate 73gthe preparation is done as follows. 60 ml of water is added to 150 ml syrup. I warm this up to about 60 degrees and in it I loose my crushed powders in it. After complete solution I add 6ml raspberry aroma and then I ling with water to 300ml. Now the problem is that the Pati ë NT regularly comes back that there is a Crystallization has occurred. I can perhaps assume this, as the Martindale considers that it is an oversaturated solution. The solubility of the disodium phosphate in water would amount to only 1 in 8. But then why the one time and not the other time. However, I also always inquire whether the bottle is not kept too cold and whether it is always shaken to remain homogeneous, but the Pati ë NT says that he always takes care of this.
potassium dihydrogen phosphate 17.5 g
Sirupus simplex 150ml
raspberry Aroma 6ml
Aqua ad 300ml
Answer
The phosphate siropes give me copbrekens. Because it is not obvious to find the right figures of solubility. I don't find any constant values. I got from a different angle a formula similar to yours but with 1 big difference anyway. The quantity of disodium phosphate is 63g instead of 73. And this seems to me something better. The same colleague signals me that the amount of sugar syrup is very important. Therefore, the phosphates must be dissolved in a minimum amount of water. The temperature of dissolving seems to me OK in eg 60 ml of water (as you do) but all the rest until 300 ml becomes sugar syrup now.