Establishment of the Chromatographic Fingerprint of Industrial 3, 5-Dinitrobenzoic Acid by High Performance Liquid Chromatography-Ultraviolet Spectrometry

A reliable reversedphase high performance liquid chromatographyultraviolet spectrometric method has been developed for drawing chromatographic fingerprint of 3,5-dinitrobenzoic acid for industrial use. Separation of 3,5-dinitrobenzoic acid and its relative impurities were achieved on a Kromasil C18 column by using methanolwater0.10% perchloric acid (V/V/V= 25/45/30) as a mobile phase at a flow rate of 1.0 mL/min. And the determination was carried out by UV spectrometry at wavelength of 254 nm. Accordingly, the chromatographic fingerprint of 3,5dinitrobenzoic acid could be established by analyzing a lot of samples and extracting their common peaks which are of representative features for all samples involved. For a given sample, the retention time, UV spectrum and area of all peaks were compared with the proposed chromatographic fingerprint, and a new protocol was then developed, by which the quality of 3,5-dinitrobenzoic acid can be controlled. This method is accurate and credible in determination of every component in an industrial product. It is also visualized and convenient in quality control. In addition, it was expounded that “integrity” and “definitude” should be elementary attributes and developing direction of the chromatographic fingerprint of fine chemical intermediate.