Sodium Cobaltinitrite LR is a water-soluble compound which is most commonly utilized for determination of potassium, ammonium, & thallium ions. It is known to have molecular formula CoN6Na3O12 with a molar mass of 403.933 g/mol.
A new qualitative test for potassium was described by Kamm and Burgess1:- By the addition of sodium cobaltinitrite to a potassium solution containing silver ions an extremely insoluble orange-yellow precipitate of potassium silver cobalti- nitrite is produced.
Dissolve 1.583 g of potassium chloride in water, and dilute with water to 500 mL. To 10.0 mL of this solution (20 mg of K2O) in a 50 mL beaker, add 2 mL of 1 N nitric acid and 8 mL of water. Dissolve 5 g of the sodium cobaltinitrite in water, dilute with water to 25 mL, and filter.
In geochemical analysis, sodium cobaltinitrite is used to distinguish alkali feldspars from plagioclase feldspars in thin section.