0.05 M Zinc Sulfate VS

This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition

Issued and maintained by the United States Pharmacopeial Convention (USP)

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Dissolve 14.4 g of zinc sulfate heptahydrate in water to make 1 L.

1 Standardization

See Volumetric Solutions. 1. Introduction.

See Titrimetry (541).

Standardize by one of the following procedures. [NOTE-Other standardization procedures may be used. See Volumetric Solutions. 2. Preparation and Standardization, 2.3 Standardization.

1.1 Standardization with visual endpoint

Accurately measure about 10 mL of 0.05 M edetate disodium VS into a 125-mL conical flask, and add, in the order given, 10 mL of acetic acid-ammonium acetate buffer TS, 50 mL of alcohol, and 2 mL of dithizone TS. Titrate with the zinc sulfate solution to a clear rose-pink color.

                   M = (mL edetate disodium x  M edetate disodium)/ (mL ZnSO₄)

1.2 Standardization with potentiometric endpoint

Accurately measure about 10 mL of 0.05 M edetate disodium VS into a 125-mL conical flask, and add, in the order given, 10 mL of acetic acid-ammonium acetate buffer TS, 50 mL of alcohol, and 1 mL of Copper-EDTA complex solution. Titrate with the zinc sulfate solution using a copper ion-selective electrode.

                   M = (mL edetate disodium x  M edetate disodium)/ (mL ZnSO₄)

[NOTE-If this volumetric solution is used in a qualitative application such as pH adjustment, dissolution medium, or diluent, its standardization is not required.]