Imaging Peptide and Protein Chirality via Amino Acid Analysis by Chiral × Chiral Two-Dimensional Correlation Liquid Chromatography

The present contribution illustrates the utilization of a chiral × chiral two-dimensional liquid chromatography (2DLC) setup with tert-butylcarbamoyl quinine chiral stationary phase (CSP) in the first dimension (1D) and tert-butylcarbamoyl quinidine CSP in the second dimension (2D) to analyze FMOC-derivatized d and l amino acids from peptide hydrolysates. Hereby, in the 1D and 2D chiral separation dimensions factors such as selector and immobilization chemistry of the CSPs, mobile phase, temperature, column hardware dimensions, stationary phase supports, particle type and packing were identical. Orthogonality between 1D and 2D CSPs was solely based on their stereochemistry, i.e. their opposite configurations in two chiral centers of the selector molecules, which results in inversion of enantiomer elution orders in the two dimensions. Using Coreshell CSPs for fast chromatography allowed 2D-flow rates which were 60 times faster than the 1D-flow rates to enable online comprehensive two-dimensional chromatogr...