May Meeting

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May 18, 2022
6:00pm – Leena Pade, UMD
6:10pm – Erik Regalado, Merck

Deep Proteomics to Uncover Heterogeneity from Limited Embryonic Tissues Using Enhanced Separation Technology
Leena Pade, University of Maryland (recipient of the WCDG Georges Guiochon Student Award)

Enantioselective UHPLC Screening Combined with In Silico Modeling for Streamlined Development of Ultrafast Enantiopurity Assays
Erik Regalado, Merck Research Laboratories, Merck & Co.

Enantioselective chromatography has been the preferred technique for the determination of enantiomeric excess across academia and industry. Although sequential multicolumn enantioselective supercritical fluid chromatography screenings are widespread, access to automated ultra-high-performance liquid chromatography (UHPLC) platforms using state-of-the-art small particle size chiral stationary phases (CSPs) is an underdeveloped area. Herein, we introduce a multicolumn UHPLC screening workflow capable of combining 14 columns (packed with sub-2 μm fully porous and sub-3 μm superficially porous particles) with nine mobile phase eluent choices. This automated setup operates under a vast selection of reversed-phase liquid chromatography, hydrophilic interaction liquid chromatography, polar-organic mode, and polar-ionic mode conditions with minimal manual intervention and high success rate. Examples of highly efficient enantioseparations are illustrated from the integration of chiral screening conditions and computer-assisted modeling. Furthermore, we describe the nuances of in silico method development for chiral separations via second-degree polynomial regression fit using LC simulator (ACD/Labs) software. The retention models were found to be very accurate for chiral resolution of single and multicomponent mixtures of enantiomeric species across different types of CSPs, with differences between experimental and simulated retention times of less than 0.5%. Finally, we illustrate how this approach lays the foundation for a streamlined development of ultrafast enantioseparations applied to high-throughput enantiopurity analysis and its use in the second dimension of two-dimensional liquid chromatography experiments.

Erik L. Regalado is currently a Principal Scientist at Merck Research Laboratories where he leads the Method Screening and Purifications group. Erik has taken on a series of scientific leadership roles within the MRL’s AR&D department to enabling analytical and preparative technologies for the development of long-term commercial manufacturing routes of new medicines and vaccines. He previously completed his postdoctoral research with Dr. Christopher J. Welch at MRL’s PR&D department on new automated screening and high-throughput analysis technologies. He obtained his Ph.D. on marine natural chemistry working with Prof. Olivier P. Thomas at the University of Nice Sophia Antipolis, France, and Prof. Clara Nogueiras at the University of Havana. Erik has 100+ publications and 2 patents with 15+ cover arts, for a total of 3000+ literature citations and an h-index of 33. He has given 60+ oral and poster presentations at scientific conferences. Erik is the recipient of the Emerging Leader in Chromatography (2021), ACS Young Investigator Award (2019) and Merck Green & Sustainable Science (2020 and 2019), among other awards. His research interest includes automated method screenings, multidimensional chromatography, high-throughput analysis, ultrafast and computer-assisted separations. Erik’s research has been highlighted on multiples scientific outlets and blogs including: C&EN, Synfacts, Nature, In the Pipeline, ChemistryWorld, Sigma-Aldrich, LCGC among others.

New to analytical chemistry or looking to sharpen your skills? Visit NIST’s site for videos and PowerPoints on Tutorials in Analytical Chemistry