A: Infrared Absorption á197Kñ.

B: Ultraviolet Absorption á197Uñ—

C: The RFvalue of the principal blue spot obtained from the Test preparationcorresponds to that obtained from the Standard preparationin the chromatogram prepared as directed in the test for Related alkaloids.

Test solution: 5mg per mL,in water.

Adsorbent: 0.25-mm layer of chromatographic silica gel mixture.

Solvent mixture— Prepare a mixture of alcohol and ammonium hydroxide (9:1).

Standard preparation— Prepare a solution of USP Ergonovine Maleate RSin Solvent mixturehaving a known concentration of about 10mg per mL.

Standard dilutions— Prepare a series of dilutions of the Standard preparationin Solvent mixturehaving known concentrations of about 0.20,0.10,and 0.05mg per mL.Use immediately after preparation.

Test preparation— Immediately prior to use,prepare a solution of Ergonovine Maleate in Solvent mixturehaving a concentration of about 10mg per mL.

Application volume: 5µL.

Developing solvent system: a mixture of chloroform,methanol,and water (75:25:3),equilibrated for 30minutes.

Procedure— Apply 5-µLportions of the Standard preparation,each of the three Standard dilutions,and the Test preparation,and proceed as directed for Thin-Layer Chromatographyunder Chromatography á621ñ.Locate the spots on the plate by spraying thoroughly and evenly with a solution prepared by dissolving 1g of p-dimethylaminobenzaldehyde in a cooled mixture of 50mLof alcohol and 50mLof hydrochloric acid.Immediately dry in a stream of nitrogen for about 2minutes:the RFvalue of the principal spot obtained from the Test preparationcorresponds to that obtained from the Standard preparation.Estimate the concentration of any other spots observed in the chromatogram of the Test preparationby comparison with the Standard dilutions.The spots from the 0.20,0.10,and 0.05mg per mLdilutions are equivalent to 2.0%,1.0%,and 0.50%of impurities,respectively.The sum of the impurities is not greater than 2.0%.

Standard preparation— Using a suitable quantity of USP Ergonovine Maleate RS,accurately weighed,prepare a solution in water having a known concentration of about 40µg per mL.

Assay preparation— Transfer about 40mg of Ergonovine Maleate,accurately weighed,to a 100-mLvolumetric flask,dilute with water to volume,and mix.Dilute 10.0mLof this solution with water to 100.0mL.

Procedure— Transfer 5.0mLeach of the Standard preparation,the Assay preparation,and water to provide a blank,to separate conical flasks.Add 10.0mLof p-dimethylaminobenzaldehyde TSwith constant swirling to each,and allow to stand for 20minutes.Concomitantly determine the absorbances of the solutions in 1-cm cells at the wavelength of maximum absorbance at about 555nm,with a suitable spectrophotometer,against the blank.Calculate the quantity,in mg,of C19H23N3O2·C4H4O4taken by the formula: in which Cis the concentration,in µg per mL,of USP Ergonovine Maleate RSin the Standard preparation,and AUand ASare the absorbances of the solutions from the Assay preparationand the Standard preparation,respectively.