According to the United States Pharmacopeia and the National Formulary (USP-NF 2024 Issue 3*), analysis of IMPURITIES in malic acid should be carried out with a 6.5 mm (I.D.) x 30 cm (length) column filled with L17 packing material and meets the following system suitability requirements. An ion-exclusion chromatography column, SUGAR SH1011, confirmed the requirements were met. Note that since the SH1011 column has a different inner diameter from the column specified in the monograph, injection volume and flow rate were adjusted in accordance with the "General Chapters" section "Chromatography ‹621›" of the USP-NF.

System suitability requirements

Resolution of maleic acid and malic acid: ≥ 2.5
Resolution of malic acid and fumaric acid: ≥ 7.0
Relative standard deviation (RSD) of maleic acid peak area (6 repeated injections): ≤ 2.0%

*The version at the time of the application acquisition.

Sample: 30 µL
(System suitability solution)

1. 1.Maleic acid 4 µg/mL
2. 2.Malic acid 1 mg/mL
3. 3.Fumaric acid 10 µg/mL