Vanillin

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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C₈H₈O₃     152.15

Benzaldehyde, 4-hydroxy-3-methoxy-;

Vanillin CAS RN®: 121-33-5.

1 DEFINITION

Vanillin contains NLT 97.0% and NMT 103.0% of vanillin (C₈H₈O₃), calculated on the dried basis. 

2 IDENTIFICATION

Change to read:

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

Change to read:

B. Spectroscopic Identification Tests 〈197〉, Ultraviolet-Visible Spectroscopy: 197U (CN 1-May-2020)

Sample solution: 8 µg/mL in methanol

Acceptance criteria: Meets the requirements

3 ASSAY

Procedure

Standard solution: 8 µg/mL of USP Vanillin RS in methanol

Sample solution: 8 µg/mL of Vanillin in methanol

Blank: Methanol

3.1 Instrumental conditions

(See Ultraviolet-Visible Spectroscopy 〈857〉.)

Mode: UV

Analytical wavelength: 308 nm

Cell: 1 cm

3.2 Analysis

Samples: Standard solution, Sample solution, and Blank

Calculate the percentage of vanillin (C₈H₈O₃) in the portion of Vanillin taken:

Result = (A_U /A_S ) × (C_U /C_S ) × 100

A_U = absorbance of the Sample solution

A_S = absorbance of the Standard solution

C_S = concentration of USP Vanillin RS in the Standard solution (µg/mL)

C_U = concentration of the Sample solution (µg/mL)

Acceptance criteria: 97.0%–103.0% on the dried basis

4 IMPURITIES

Residue on Ignition 〈281〉: NMT 0.05%

5 SPECIFIC TESTS

Melting Range or Temperature 〈741〉: 81°–83°

Loss on Drying 〈731〉: Dry the sample over silica gel for 4 h: it loses NMT 1.0% of its weight.

6 ADDITIONAL REQUIREMENTS

Packaging and Storage: Preserve in tight, light-resistant containers.

USP Reference Standards 〈11〉

USP Vanillin RS