Correct me if I am wrong but food grade is the highest purity isn't it?
No, food grade just means no pathogens and safe to consumption, it doesn't say anything about the chemical purity - they may contain several percent of inert stuff (which will mean you have no idea what is the concentration of solutions you make), or even worse - stuff that is perfectly safe, but is chemically completely off when it comes to controlling pH.
High purity (as in over 99% of the main component) is analytical grade (these don't have to be safe for consumption, so they can contain traces of toxic contaminants - not that they do, just nobody cares).
Unfortunately that means that most of the things you have are useless. Citric acid and trisodium phosphate can be used to prepare buffers covering very wide pH range, but if your citric acid is just food grade I wouldn't trust it too much. You can try to recrystallize it, that should help, but it is still not guaranteed to OK.
Saturated at 25°C means you have a solution that contains undissolved solid at the bottom (that guarantees nothing more can dissolve - which is definition of "saturation" here).
Are you sure you need very high precision measurements?
Borek from what I understand Mrs. Wages pickling lime is food grade pure calcium hydroxide.
See above - food grade and pure are different things. Plus, calcium hydroxide is a base and - as I wrote earlier - it will easily absorb CO2
from the atmosphere, so it is contaminated with CaCO3
. Doesn't matter much for pickling, substantially changes the pH of the saturated solution.