Menadione
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1,4-Naphthalenedione,2-methyl-.
2-Methyl-1,4-naphthoquinone [58-27-5].
»Menadione contains not less than 98.5percent and not more than 101.0percent of C11H8O2,calculated on the dried basis.
Caution—Menadione powder is irritating to the respiratory tract and to the skin,and a solution of it in alcohol is a vesicant.
Packaging and storage—
Preserve in well-closed,light-resistant containers.Store at 25
,excursions permitted between 15and 30.
,excursions permitted between 15and 30.
Identification—
A:Infrared Absorption á197Kñ.
B:Ultraviolet Absorption á197Uñ—
Solution:
5µg per mL.
Medium:
alcohol.
Absorptivities at 250nm,calculated on the dried basis,do not differ by more than 3.0%.
Loss on drying á731ñ—
Dry it over silica gel for 4hours:it loses not more than 0.3%of its weight.
Residue on ignition á281ñ:
not more than 0.1%.
Ordinary impurities á466ñ—
Test solution:
methanol.
Standard solution:
methanol.
Eluant:
chloroform.
Visualization:
1.
Assay—
Accurately weigh about 150mg of Menadione,and transfer to a 150-mLflask.Add 15mLof glacial acetic acid and 15mLof 3Nhydrochloric acid,and rotate the flask until the Menadione is dissolved.Then add about 3g of zinc dust,close the flask with a stopper bearing a Bunsen valve,shake,and allow to stand in the dark for 1hour,with frequent shaking.Rapidly decant the solution through a pledget of cotton into another flask,immediately wash the reduction flask with three 10-mLportions of freshly boiled and cooled water,add 0.1mLof orthophenanthroline TS,and immediately titrate the combined filtrate and washings with 0.1Nceric sulfate VS.Perform a blank determination,and make any necessary correction.Each mLof 0.1Nceric sulfate is equivalent to 8.609mg of C11H8O2.
Auxiliary Information—
Staff Liaison:Andrzej Wilk,Ph.D.,Senior Scientific Associate
Expert Committee:(PA5)Pharmaceutical Analysis 5
USP28–NF23Page 1204
Pharmacopeial Forum:Volume No.29(5)Page 1531
Phone Number:1-301-816-8305