Compositional Analysis of Complex Mixtures using Automatic MicroED Data Collection

Quantitative analysis of complex mixtures, including compounds having similar chemical properties, is demonstrated using an automatic and high throughput approach to microcrystal electron diffraction (MicroED). Compositional analysis of organic and inorganic compounds can be accurately executed without the need of diffraction standards. Additionally, with sufficient statistics, small amounts of compounds in mixtures can be reliably detected. These compounds can be distinguished by their crystal structure properties prior to structure solution. In addition, if the crystals are of good quality, the crystal structures can be generated on the fly, providing a complete analysis of the sample. MicroED is an effective method for analyzing the structural properties of sub‐micron crystals, which are frequently found in small‐molecule powders. By developing and using an automatic and high throughput approach to MicroED, and with the use of SerialEM for data collection, data from thousands of crystals allow sufficient statistics to detect even small amounts of compounds reliably. Quantitative analysis of complex mixtures, including chemically similar compounds, is demonstrated using an automatic and high throughput approach to MicroED. Compositional analysis can be accurately executed without the need of diffraction standards. Compounds are distinguished by their structure properties prior to structure solution. With sufficient statistics, small amounts of compounds in mixtures can be reliably detected. The crystal structures can be directly solved providing good quality data.