C6H6Cl6 290.83

Cyclohexane, 1,2,3,4,5,6-hexachloro-, (1,2,3,4,5,6)-.
-1,2,3,4,5,6-Hexachlorocyclohexane [58-89-9].

Packaging and storage— Preserve in well-closed containers.

USP Reference standards 11— USP Lindane RS.

Identification, Infrared Absorption 197K.

Congealing temperature 651: not less than 112.0.

Water, Method I 921: not more than 0.5%.

Chloride ion— Place about 100 mg in a test tube with 10 mL of water, shake, and filter. Add 1 mL of nitric acid and 3 mL of silver nitrate TS to the filtrate: no turbidity develops.

Residual solvents 467: meets the requirements.

Assay— Transfer about 400 mg of Lindane, accurately weighed, to a wide-mouth, glass-stoppered, 250-mL conical flask, add 20 mL of alcohol, and warm on a steam bath until solution is complete. Cool, add 20 mL of a 1 in 20 solution of potassium hydroxide in alcohol, swirl gently, and allow to stand for 10 minutes. Dilute with water to about 100 mL, neutralize with 2 N nitric acid, and add 5 mL in excess. Pipet into the solution 50 mL of 0.1 N silver nitrate VS, then add 5 mL of nitrobenzene, and shake vigorously. Add ferric ammonium sulfate TS, and titrate the excess silver nitrate with 0.1 N ammonium thiocyanate VS. Perform a blank determination (see Residual Titrations under Titrimetry 541). Each mL of 0.1 N silver nitrate is equivalent to 9.694 mg of C6H6Cl6.

Expert Committee : (MDAA05) Monograph Development-Antivirals and Antimicrobials

USP29–NF24 Page 1258

Phone Number : 1-301-816-8394