Succinic Acid

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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C₄H₆O₄ 118.09

Butanedioic acid CAS RN®: 110-15-6.

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1 DEFINITION

Succinic Acid contains NLT 98.0% and NMT 102.0% (RB 1-Jun-2024) of succinic acid (C₄H₆O₄ ).

2 IDENTIFICATION

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K

B. Chromatographic Identity

The retention time of the major peak of the Sample solution corresponds to that of the Standard solution, as obtained in the Assay.

3 ASSAY

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Procedure

Diluent: Dissolve 6.8 g of potassium phosphate, monobasic in 2 L of water. Adjust the pH of the solution to 2.3 with drops of phosphoric acid.

This solution is 25 mM potassium phosphate buffer, pH 2.3.

Mobile phase: Methanol and Diluent (8:92)

System suitability solution: 1.0 mg/mL of USP Succinic Acid RS and 0.003 mg/mL of USP Fumaric Acid RS in Diluent

Standard solution: 1.0 mg/mL of USP Succinic Acid RS in Diluent

Sample solution: 1.0 mg/mL of Succinic Acid in Diluent

Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 204 nm

Column: 4.6-mm × 15-cm; 3-μm packing L1

Flow rate: 1.0 mL/min

Injection volume: 20 μL

System suitability

Sample: System suitability solution

[Note—The relative retention times for succinic acid and fumaric acid are 1.0 and 1.2, respectively.]

Suitability requirements

Resolution: NLT 2.0 between succinic acid and fumaric acid

Relative standard deviation: NMT 0.5% for the succinic acid peak

Tailing factor: 0.8–2.0

Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of succinic acid (C₄H₆O₄ ) in the portion of Succinic Acid (RB 1-Jun-2024) taken:

Result = (r_U/r_S ) × (C_S /C_U ) × 100

r_U = peak response from the Sample solution

r_S = peak response from the Standard solution

C_S = concentration of USP Succinic Acid RS in the Standard solution (mg/mL)

C_U = concentration of Succinic Acid in the Sample solution (mg/mL)

Acceptance criteria: 98.0%–102.0% (RB 1-Jun-2024)

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.025%

5 SPECIFIC TESTS

Melting Range or Temperature 〈741〉: 185.0°–190.0°

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in a well-closed container. No storage requirements specified.

USP Reference Standards 〈11〉

USP Fumaric Acid RS

USP Succinic Acid RS