Direct specific rotation measurements of amino acids,dipeptides, and tripeptides by laser‐based polarimetry

This paper addresses direct HPLC detection of amino acids, di and tripeptides via laser‐based polarimetry. Mass detection limits typically range from 0.5 to 50 μg injected on‐column, corresponding to concentration levels from 0.1 to 1 mg/ml. These levels are 1 to 2 orders of magnitude lower than measurements with conventional polarimetry, implying that concentration‐dependent phenomena (e.g., solute dimerization) are minimized. This is the first published report of the specific rotation of the di and tripeptides of Ala and Phe. The relationship between pH and specific rotation of selected amino acids, peptides, and lysozyme is described. Chirality 11:187–194, 1999. © 1999 Wiley‐Liss, Inc.