Hi, guys,
I want to know how to identify the Calcium ion from a solution which contains both of Calcium ion and Magnesium ion.
I try to use the USP method to identify the Calcium. However, I am afraid the Magnesium salts are also precipitated.
USP method is as follows.
Calcium—Solutions of calcium salts form insoluble oxalates when treated as follows. To a solution of the calcium salt (1 in
20) add 2 drops of methyl red TS, and neutralize with 6 N ammonium hydroxide. Add 3 N hydrochloric acid, dropwise, until
the solution is acid to the indicator. Upon the addition of ammonium oxalate TS, a white precipitate is formed.