Enantiomer Separation of D‐L Branched Amino Acids by Capillary Electrophoresis in Sport Nutritional Supplements

Abstract

ABSTRACT A capillary electrophoresis method was developed for the chiral separation of D‐L valine, isoleucine, and leucine. The separation of derivatized amino acids with 9‐fluorenylmethyl‐chloroformate was performed by micellar electrokinetic capillary chromatography. We optimized the method by varying β‐cyclodextrin and sodium dodecyl sulphate concentrations in the presence of 2‐propanol. The proposed method was applied to the determination of D‐forms of valine, Isoleucine, and leucine in the presence of an excess of relative L forms, in commercial supplements for sport nutrition. Results demonstrated that the separation of enantiomers was possible up to an enantiomeric ratio of 1:100. The analysis of selected products confirmed the enantiomeric purity of utilized amino acids.