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Witch Hazel
» Witch Hazel is a clear, colorless distillate prepared from recently cut and partially dried dormant twigs of Hamamelis virginiana Linné.
Prepare Witch Hazel as follows. Macerate a weighed amount of the twigs for about 24 hours in about twice their weight of water, then distill until not less than 800 mL and not more than 850 mL of clear, colorless distillate is obtained from each 1000 g of the twigs taken. Add 150 mL of Alcohol to each 850 mL of distillate, and mix thoroughly.
Packaging and storage
Preserve in tight containers, and avoid exposure to excessive heat.
Specific gravity
pH
Nonvolatile residue
Evaporate 100 mL to dryness in a tared dish on a hot plate at 60
Limit of tannins
Mobile phase A
Adjust 1000 mL of water with phosphoric acid to a pH of 2.5 ± 0.1. Filter and degas.
Mobile phase B
Use filtered and degassed acetonitrile.
Standard solution
Dissolve an accurately weighed quantity of tannic acid in water to obtain a solution having a known concentration of about 0.03 mg of tannic acid per mL.
Test solution
Use Witch Hazel.
Chromatographic system
(see Chromatography
Procedure
Separately inject equal volumes (about 25 µL) of the Standard solution and the Test solution into the chromatograph, record the chromatograms, and measure the responses for all peaks. If any peak corresponding to the retention time of tannic acid in the Standard solution is present in the chromatogram of the Test solution, its peak area is no more than that of the tannic acid in the Standard solution.
Auxiliary Information
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USP32NF27 Page 3874
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