A: Infrared Absorption 197K.

B: Ultraviolet Absorption 197U—

Test solution: 10 mg per mL, in dioxane.

Solvent— Use dimethyl sulfoxide.

(Official January 1, 2007)

Standard preparation— Prepare as directed under Single-Steroid Assay 511, using USP Testosterone RS.

Assay preparation— Accurately weigh about 20 mg of Testosterone, previously dried; dissolve in a sufficient quantity of a mixture of equal volumes of alcohol and chloroform to make 10.0 mL; and mix.

Procedure— Proceed as directed for Procedure under Single-Steroid Assay 511, using a solvent system consisting of a mixture of benzene and ethyl acetate (1:1), through the fourth sentence of the second paragraph under Procedure. Then centrifuge the tubes for 5 minutes, and determine the absorbances of the supernatant in 1-cm cells at the wavelength of maximum absorbance at about 241 nm, with a suitable spectrophotometer, against the blank. Calculate the quantity, in mg, of C19H28O2 in the portion of Testosterone taken by the formula: in which C is the concentration, in mg per mL, of USP Testosterone RS in the Standard preparation; and AU and AS are the absorbances of the solutions from the Assay preparation and the Standard preparation, respectively.