0.1 N Sulfuric Acid 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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Transfer 100 mL of 1 N sulfuric acid VS to a 1000-ml volumetric flask. Dilute with water to volume.

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 weigh about 100 mg of tromethamine, dried according to the label instructions or, if this information is not available, dried at 105" for 3 h. Dissolve in 50 ml of water and add 2 drops of bromocresol green TS. Titrate with the sulfuric acid solution to a pale yellow endpoint.

N = [mg tromethamine x (Assay/100)]/ (121.14 x mL H₂SO₄)

Where the Assay is the potency/content of tromethamine.

1.2 Standardization with potentiometric endpoint

Accurately weigh about 100 mg of tromethamine, dried according to the label instructions or, if this information is not available, dried at 105° for 3 h. Dissolve in 50 mL of water. Titrate with sulfuric acid solution. Determine the endpoint potentiometrically with a pH electrode.

N = [mg tromethamine x (Assay/100)]/ (121.14 x mL H₂SO₄)

Where the Assay is the potency/content of tromethamine.

[NOTE-If this volumetric solution is used in a qualitative application such as pH adjustment, dissolution medium, or diluent, its standardization is not required.] _{▲(USP 1-DEC-2022)}