Characterization of Impurity Profile of Dimercaptosuccinate Using High-Performance Liquid Chromatography and Mass Spectrometry

As one of the key components in technetium-labeled radiopharmaceuticals, the quality of the dimercaptosuccinate (DMSA) plays a critical role in determining the safety and efficacy of the final drug product. However, due to its high polarity and susceptibility to oxidation, comprehensive characterization of the impurity profile of DMSA remains challenging. In this study, high-performance liquid chromatography and mass spectrometry were employed to achieve a systematic and thorough analysis of DMSA-related impurities. First, an HPLC-UV method was developed to enable baseline separation of DMSA and its impurities. Subsequently, a two-dimensional liquid chromatography–tandem mass spectrometry (2D-LC-MS/MS) approach was applied to identify six structurally diverse impurities present in DMSA. The developed HPLC method was rigorously validated and demonstrated to be sensitive, robust, and suitable for the accurate quantification and detection of trace impurities. Using the validated method, DMSA raw materials sourced from multiple manufacturers were analyzed, revealing significant variability in their impurity profiles. These findings underscore the importance of stringent quality control measures for DMSA in radiopharmaceutical manufacturing. This work not only establishes a reliable analytical framework for impurity profiling and structural elucidation of DMSA but also provides valuable insights for the development of quality control strategies and process optimization of radiopharmaceuticals.