Adenine

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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C₅H₅N₅       135,13

9H-Purin-6-amine;

1,6-Dihydro-6-iminopurine CAS RN^®: 73-24-5; UNII: JAC85A2161.

1 DEFINITION

Adenine contains NLT 98.0% and NMT 102.0% of adenine (C₅H₅N₅ ), calculated on the dried basis.

2 IDENTIFICATION

Change to read:

A. Spectroscopic Identification Tests 〈197〉, Infrared Spectroscopy: 197K (CN 1-May-2020)

B. 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

3.1 Procedure

Buffer solution: Dissolve 6.90 g of monobasic ammonium phosphate in about 800 mL of water. Adjust with ammonium hydroxide to a pH of 6.2, and dilute with water to 1 L.

Mobile phase: See Table 1.

Table 1

System suitability solution: 50 µg/mL each of USP Adenine RS and 7-methyladenine in water

Standard solution: 0.1 mg/mL of USP Adenine RS in water. If necessary, sonicate the solution at 30° until the substance is completely dissolved.

Sample solution: 0.1 mg/mL of Adenine in water. If necessary, sonicate the solution at 30° until the substance is completely dissolved. Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 260 nm

Column: 4.6-mm × 25-cm; 5-µm packing L85

Flow rate: 1.0 mL/min

Injection volume: 10 µL

System suitability

Sample: System suitability solution

[Note—The relative retention times for 7-methyladenine and adenine are 0.88 and 1.0, respectively.]

Suitability requirements

Resolution: NLT 2.0 between the 7-methyladenine and adenine peaks

3.2 Analysis

Samples: Standard solution and Sample solution

Calculate the percentage of adenine (C5H5N5) in the portion of Adenine 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 Adenine RS in the Standard solution (mg/mL)

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

Acceptance criteria: 98.0%–102.0% on the dried basis

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.1%

Related Compounds

4.1 Buffer solution, Mobile phase, System suitability solution, Standard solution, and System suitability: Proceed as directed in the Assay. Sample solution

Dissolve 25 mg of Adenine in approximately 15 mL of boiling water. Cool, quantitatively transfer to a 25-mL volumetric ask, and dilute with water to volume.

4.2 Chromatographic system

(See Chromatography 〈621〉, System Suitability.)

Mode: LC

Detector: UV 240 nm

Column: 4.6-mm × 25-cm; 5-µm packing L85

Flow rate: 1.0 mL/min

Injection volume: 20 µL

4.3 Analysis

Sample: Sample solution

Calculate the percentage of each impurity in the portion of Adenine taken:

Result = (r_U /r_T ) × 100

r_U = peak response of each impurity from the Sample solution

r_T = sum of all the peak responses from the Sample solution

4.4 Acceptance criteria

Individual impurity: NMT 0.1%

Total impurities: NMT 2.0%

5 SPECIFIC TESTS

Loss on Drying 〈731〉: Dry a sample at 110° for 4 h: it loses NMT 1.0% of its weight.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in well-closed containers.

USP Reference Standards 〈11〉

USP Adenine RS