0.1 M Tetramethylammonium Chloride 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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(USP 1-Dec-2022)

Dissolve 10.96 g of tetramethylammonium chloride (CH₃), NCIA (USP 1-Dec-2022) in water to make 1000 ml..

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

(USP 1-Dec-2022) Transfer an accurately measured volume of about 40 mL of the solution to a flask, add 10 mL of diluted nitric acid and 50.0 mL of 0.1 N silver nitrate VS, and mix. Add 5 mL of nitrobenzene and 2 mL of ferric ammonium sulfate TS, shake, and titrate the excess silver nitrate with 0.1 N ammonium thiocyanate VS.

1.2 Standardization with potentiometric endpoint

Transfer an accurately measured volume of about 10 mL of the solution to a flask, add 2 mL of diluted nitric acid, and titrate with 0.1 N silver nitrate VS using a combined silver electrode.

M = (ml AgNO3 x N AgNO3)/ml (CH3)4NCI

(USP 1-Dec-2022)

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