Unless otherwise specified in an individual monograph, prepare a solution to contain 0.1 g of the sodium compound in 2 mL of water.
Add 2 mL of 15% potassium carbonate, and heat to boiling.
No precipitate is formed.
Add 4 mL of potassium pyroantimonate TS, and heat to boiling.
Allow to cool in ice water and, if necessary, rub the inside of the test tube with a glass rod.
A dense precipitate is formed.
Sodium compounds impart an intense yellow color to a nonluminous flame.