A:Thin-Layer Chromatographic Identification Test ¨¢201ñ¡ª

B: The retention time of b-sitosterol in the chromatogram of the Test solutioncorresponds to that in the chromatogram of the Standard solution,as obtained in the test for Content of b-sitosterol.

C: The retention time of scopoletin in the chromatogram of the Test solutioncorresponds to that in the chromatogram of the Standard solution,as obtained in the test for Content of scopoletin.

pH5.5Acetate buffer,Reagent solution,and Standard solution¡ª Proceed as directed for Content of total amino acidsunder Stinging Nettle.

Test solution¡ª Dissolve 50mg of Powdered Extract,accurately weighed,in 80mLof water,shake for 10minutes,dilute with water to 100mL,and filter.

Procedure¡ª Proceed as directed for Content of total amino acidsunder Stinging Nettle,except to calculate the percentage of total amino acids taken by the formula:
in which WUis the weight,in mg,of the Powdered Extract in the Test solution;and the other terms are as defined therein:not less than 5.0%of total amino acids is found.

Derivatizing reagent,Internal standard solution,Standard solution,and Chromatographic system¡ª Proceed as directed for Content of b-sitosterolunder Stinging Nettle.

Test solution¡ª Transfer 20.0g of Powdered Extract,accurately weighed,to a Soxhlet apparatus,treat with chloroform,and extract for 6hours.The volume of chloroform used is at least twice the volume of the thimble with an appropriate-size flask.Dry the solvent under reduced pressure,add 1.0mLof Internal standard solution,and dilute with chloroform to 10mL.Transfer 0.5mLof this solution to a 10-mLround-bottomed flask,dry the solvent under reduced pressure,and add 0.5mLof Derivatizing reagent.

Procedure¡ª Proceed as directed for Content of b-sitosterolunder Stinging Nettle,except to calculate the percentage of b-sitosterol in the portion of Powdered Extract taken by the formula:
in which CUis the concentration,in mg per mL,of Powdered Extract in the Test solution;and the other terms are as defined therein:not less than 0.1%of b-sitosterol is found.

Solution A,Solution B,Mobile phase,Standard solution,and Chromatographic system¡ª Proceed as directed for Content of scopoletinunder Stinging Nettle.

Test solution¡ª Dissolve 200mg of Powdered Extract,accurately weighed,in 25mLof methanol,place in an ultrasonic bath for 25minutes,and centrifuge.Transfer 0.5mLof this solution to a 10-mLvolumetric flask,and dilute with methanol to volume.

Procedure¡ª Proceed as directed for Content of scopoletinunder Stinging Nettle,except to calculate the content of scopoletin (C10H8O4)in the portion of Powdered Extract taken by the formula:
in which CUis the concentration,in mg per mLof Powdered Extract in the Test solution;and the other terms are as defined therein:not less than 30µg per g of scopoletin is found.