Identification—
One Tablet dissolves in 100 mL of water with effervescence. The collected gas responds to the test for
Bicarbonate 
191
, and the resulting solution responds to the test for
Potassium 191.
Assay—
Assay preparation—
Transfer 10 Tablets to a 2000-mL volumetric flask, dissolve in 200 mL of water, swirl until effervescence ceases, dilute with water to volume, and mix. Filter, and quantitatively dilute an accurately measured volume of the filtrate with water to obtain a solution containing 30 µg of potassium per mL. Transfer 5.0 mL of the resulting solution to a 100-mL volumetric flask, add 2.0 mL of sodium chloride solution (1 in 5) and 1.0 mL of hydrochloric acid, dilute with water to volume, and mix.
Procedure—
Proceed as directed for
Procedure in the
Assay under
Potassium Chloride Oral Solution. Calculate the quantity, in mg, of K in each Tablet taken by the formula:
L(C / D),
in which
L is the labeled quantity, in mg, of potassium in each Tablet,
C is the concentration, in µg per mL, of potassium in the
Assay preparation, and
D is the concentration, in µg per mL, of potassium in the
Assay preparation on the basis of the labeled quantity in each Tablet and the extent of dilution.
