Magnetic nanoparticles are powerful tools over a wide range of industries, but have particularly powerful biomedical applications for clinical and research diagnostics, clinical therapy, and basic life science research. These applications require consistent sources for magnetic nanoparticles with narrow distributions of magnetic properties, but no technology is now commercially available for manufacturers or users to quantify single-particle magnetic properties with sufficient throughput to provide cost-effective, efficient quality control. Some particle uses, including magnetic separation and magnetic diagnostics, rely on superparamagnetism and suffer reduced performance, such as unwanted particle interactions and aggregation, due to ferromagnetic behavior in a subset of particles. However, this ferromagnetic particle subset can be obscured by ensemble measurements. Quantum Diamond Technologies has developed a high-throughput magnetic particle analysis platform using magnetic imaging with quantum defects in diamond. Our system can quantitatively analyze, with high sensitivity and precision, thousands of magnetic particles in parallel in a matter of minutes with a simple benchtop system. We will adapt this system in Phase I to measure ferromagnetic nanoparticles smaller than 100 nm with similar high throughput. With further development, our underlying magnetic sensing technology can additionally provide vector magnetometry, time-resolved magnetic response, and measurement of particle magnetic anisotrophy.