Potassium Chloride
(poe tas' ee um klor' ide).

KCl74.55
Potassium chloride    [7447-40-7].
DEFINITION
Potassium Chloride contains NLT 99.0% and NMT 100.5% of KCl, calculated on the dried basis.
IDENTIFICATION
•  A. Identification Tests—General, Potassium 191
Sample solution: 50 mg/mL
Acceptance criteria: Meets the requirements
•  B. Identification Tests—General, Chloride 191
Sample solution: 50 mg/mL
Acceptance criteria: Meets the requirements
ASSAY
•  Procedure
Sample: 200 mg
Analysis: Dissolve the Sample in 10 mL of water. Add 10 mL of glacial acetic acid, 75 mL of methanol, and 3 drops of eosin Y TS. Titrate, with shaking, with 0.1 N silver nitrate VS to a pink endpoint. Each mL of 0.1 N silver nitrate is equivalent to 7.455 mg of KCl.
Acceptance criteria: 99.0%–100.5% on the dried basis
IMPURITIES
•  Aluminum 206 (where it is labeled as intended for use in hemodialysis): Proceed as directed, using 2.0 g of Potassium Chloride to prepare the Test preparation.
Acceptance criteria: NMT 1 ppm
•  Sodium
Sample solution: 50 mg/mL
Acceptance criteria: Sample solution tested on a platinum wire does not impart a pronounced yellow color to a nonluminous flame.
•  Iodide
Standard stock solution: 1.64 mg/mL of potassium iodide in water
Standard solution: Dilute 1.0 mL of Standard stock solution with water to 25 mL. Dilute 2.0 mL of this solution with water to 8 mL. Add 1 mL each of chloroform and diluted hydrochloric acid, then add 2 drops of a chloramine T solution (0.1 in 100), and shake gently.
Sample solution: Dissolve 2 g of Potassium Chloride in 8 mL of water. Add 1 mL each of chloroform and diluted hydrochloric acid, then add 2 drops of a chloramine T solution (0.1 in 100), and shake gently.
Acceptance criteria: The violet color of the chloroform layer is not darker than that of a concomitantly prepared Standard solution (NMT 0.005%).
•  Bromide
Standard stock solution: 1.28 mg/mL of sodium bromide in water
Standard solution: Dilute 2.0 mL of Standard stock solution with water to 8 mL. Add 1 mL each of chloroform and diluted hydrochloric acid, then add 5 drops of a chloramine T solution (1 in 100), and shake gently.
Sample solution: Dissolve 2 g of Potassium Chloride in 8 mL of water. Add 1 mL each of chloroform and diluted hydrochloric acid, then add 5 drops of a chloramine T solution (1 in 100), and shake gently.
Acceptance criteria: The brown color of the chloroform layer is not darker than that of a concomitantly prepared Standard solution (NMT 0.1%).
•  Calcium and Magnesium
Sample solution: 10 mg/mL in water
Analysis: To 20 mL of Sample solution add 2 mL each of 6 N ammonium hydroxide, ammonium oxalate TS, and dibasic sodium phosphate TS.
Acceptance criteria: No turbidity is produced within 5 min.
•  Heavy Metals 231
Sample solution: 2.0 g in 25 mL of water
Acceptance criteria: NMT 10 ppm
SPECIFIC TESTS
•  Acidity or Alkalinity: To a solution of 5.0 g in 50 mL of carbon dioxide-free water add 3 drops of phenolphthalein TS: no pink color is produced. Then add 0.30 mL of 0.020 N sodium hydroxide: a pink color is produced.
•  Loss on Drying 731: Dry a sample at 105 for 2 h: it loses NMT 1.0% of its weight.
ADDITIONAL REQUIREMENTS
•  Packaging and Storage: Preserve in well-closed containers.
•  Labeling: Where Potassium Chloride is intended for use in hemodialysis, it is so labeled.
Auxiliary Information— Please check for your question in the FAQs before contacting USP.
Topic/QuestionContactExpert Committee
MonographMary S. Waddell
Scientific Liaison
1-301-816-8124
(SM42010) Monographs - Small Molecules 4
USP35–NF30 Page 4359
Pharmacopeial Forum: Volume No. 29(5) Page 1562
Chromatographic Column— 
Chromatographic columns text is not derived from, and not part of, USP 35 or NF 30.