Compositional Analysis of Complex Mixtures using Automatic MicroED Data Collection

Area of Science:

• Crystallography
• Materials Science
• Analytical Chemistry

Background:

• Quantitative analysis of complex mixtures with similar chemical properties is challenging.
• Sub-micron crystals are common in small-molecule powders but difficult to analyze.
• Existing methods often require diffraction standards for compositional analysis.

Purpose of the Study:

• To demonstrate an automatic and high-throughput approach to MicroED for complex mixture analysis.
• To enable accurate compositional analysis without diffraction standards.
• To reliably detect small amounts of compounds in mixtures.

Main Methods:

• Utilizing an automatic and high-throughput microcrystal electron diffraction (MicroED) workflow.
• Employing SerialEM software for automated data collection.
• Analyzing crystal structure properties for compound identification and quantification.

Main Results:

• Accurate quantitative compositional analysis of organic and inorganic compounds was achieved.
• Small amounts of compounds in mixtures were reliably detected with sufficient statistics.
• Crystal structures were generated on the fly for complete sample analysis.
• Distinguishing compounds by crystal structure properties was possible prior to structure solution.

Conclusions:

• Automatic, high-throughput MicroED is an effective method for analyzing sub-micron crystals in complex mixtures.
• The developed approach allows for accurate analysis without the need for diffraction standards.
• Sufficient data from thousands of crystals ensures reliable detection of minor components.