»Witch Hazel is a clear,colorless distillate prepared from recently cut and partially dried dormant twigs of Hamamelis virginianaLinné.
Prepare Witch Hazel as follows.Macerate a weighed amount of the twigs for about 24hours in about twice their weight of water,then distill until not less than 800mLand not more than 850mLof clear,colorless distillate is obtained from each 1000g of the twigs taken.Add 150mLof Alcohol to each 850mLof distillate,and mix thoroughly.
Packaging and storage
Preserve in tight containers,and avoid exposure to excessive heat.
Specific gravity á841ñ:
between 0.979and 0.983.
between 3.0and 5.0.
Evaporate 100mLto dryness in a tared dish on a hot plate at 60
:the weight of the residue does not exceed 25mg (0.025%).
Limit of tannins
Mobile phase A
Adjust 1000mLof water with phosphoric acid to a pHof 2.5±0.1.Filter and degas.
Mobile phase B
Use filtered and degassed acetonitrile.
Dissolve an accurately weighed quantity of tannic acid in water to obtain a solution having a known concentration of about 0.03mg of tannic acid per mL.
Use Witch Hazel.
(see Chromatography á621ñ
)The liquid chromatograph is equipped with a 280-nm detector and a 5.0-mm ×15-cm column that contains packing L1and is programmed to provide variable mixtures of Mobile phase A
and Mobile phase B.
Initially,the system is held at a mixture consisting of 90%Mobile phase A
and 10%Mobile phase B
for 5.0minutes.The proportion of Solvent B
to Solvent A
is increased linearly to 100%over the next 15minutes.The flow rate is about 1mLper minute.
Separately inject equal volumes (about 25µL)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.
Alcohol content,Method Iá611ñ:
between 14.0%and 15.0%of C2
:Gabriel I.Giancaspro,Ph.D.,Senior Scientist and Latin American Specialist