Eluant:
a mixture of methanol, glacial acetic acid, and water (8:1:1).
Visualization:
3, followed by overspraying with hydrogen peroxide TS. [NOTECover the thin-layer chromatographic plate with a glass plate to slow fading of the spots.]
Assay
Transfer about 400 mg of Tetrahydrozoline Hydrochloride, accurately weighed, to a 250-mL beaker, and dissolve in 60 mL of glacial acetic acid, heating if necessary. Add 5 mL of acetic anhydride, 5 mL of mercuric acetate TS, and 3 drops of quinaldine red TS, and titrate with 0.1 N perchloric acid VS. Perform a blank determination, and make any necessary correction. Each mL of 0.1 N perchloric acid is equivalent to 23.67 mg of C13H16N2·HCl.