This application brief provides an MS compatible method for assay of hydroxychloroquine sulfate. By enabling MS analysis, this method enhances the analytical tool-kit available for hydroxychloroquine characterization and development. MS analysis enables qualitative compound identification without the need for individual standards. Furthermore, this new method exhibits faster run times, improved resolution, and less peak tailing compared to the current USP Monograph method. Regardless of whether hydroxychloroquine serves as a potential treatment for COVID-19, improved speed may prove to be important during time-sensitive pharmaceutical manufacturing. Furthermore, more robust analytical performance may provide enhanced confidence in critical quality control environments.