FCCV标准-Zinc Oxide 氧化锌.pdf

512/ Zinc Oxide Monographs
CC V
hydration, up to the trihydrate, depending on the method of Lead Determine as directed in the Flame Alomic Absorp/ion
isolation. It is freely soluble in water and very slightly soluble Spectrophotometric Method under Lead Limit Test, Appendix
in alcohol
I11B, using a 5-y sample
Reducing Substances Transfer about I g of sample, accu-
IF unction Nulrient
rately weighed, into a 250-ml Erlenmeyer flask, dissolve in
10 ML of water, and add 25 ML ol alkaline cupric citrate TS
REQUIREMIENTS
Cover the flask with a small beaker, boil gently for exactly
5 min, and cool rapidly to room temperature. Add 25 ML o
abeling Indicate the powder or granular [orm of the a 1: 10 acetic acid solution, 10.0 ML of 0.I N iodine, 10 ml
product
of 2.7 N hydrochloric acid, and 3 ML of starch TS, and titrate
Identification
with 0.1 N sodium thiosulfate to the disappearance of the
A. A 1: 10 aqueous solution gives positive tests for Zinc, blue color. Calculate the weight, in milligrams, of reducing
Appendix IIA
substances (as D-glucose )by the formula
B. Dissolve a quantity of sample in water, healing in a water
bath at 60 if necessary, to obtain a Test Solution containing
27×(1M1-2M2)
10 mg/ml. Similarly, prepare a Standard Solution of USP n which 27 is an empirically determined equivalence actor
Poassium Gluconate Reference Standard in water. diluting for D-glucose V1 and N are the volume, in milliliters, and
to 10 mg/ml Apply separate 5-ul portions of the Tes Solu- the normality of the iodine solution, respectively; and r2 and
tion and the Standard Solution on a suitable thin-layer chro
N2 are the volume, in milliliters, and the normality of the
matographic plate(see Thin-layer Chromatography, Appen- sodium thiosulfate solution, respectively
dix TA)coated with a .25-mm layer of chromatographic Sulfate Determine as directed in the Su ate imif es under
silica gel, and allow to dry. Develop the chromatogram in a Chloride and Sufa/e Limil Tests, Appendix LB. Any Turbidity
solvent system consisting of a mixture of alcohol, water, produced by a 500-mg sample does not exceed that in a control
ammonium hydroxide, and ethyl acetate(50: 30: 10: 10)until contaiing 250)mg of sulfate($04)1on
the solvent front has moved about three-fourths of the length Water Determine as directed for Method Ib (Residual Titr-
of the plate. Remove the plate from the chamber, and dry at tion) in Method 1 (Karl Fischer Titrimetric Method)under
I 10 for 20 min Allow to cool, and spray with a spray reagent /Yater Delermination, Appendix IB
prepared as Follows: Dissolve 2.5 g of ammonium molybdate
in about 50 ml of 2 M sulfuric acid in a 100-ml volumetric Packaging and Storage Store in well-closed containers
Dlask, add 1.0 g of ceric sulfate, swirl to dissolve, dilute with
2 N sulfuric acid to volume, and mix. After spraying, heat
the plate at 1 10@ for about 10 min: The principal spot obtained
from the /es/ Solulion corresponds In color. sive. and Rr value
to that oblained from the Standard Solulion
Zinc Oxide
Assay Not less than 97.0% and not more than 102.0% o
n, calculaled on the anhydrous basis
Formula wt 813&
Cadmium Not more than 2 mg/k
Chloride Not more than 0. 05%
CAS:「1314-13-2
Lead Not more than 2 mg/kg

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