Chiral separation of unmodified α-hydroxy acids by ligand exchange HPLC using chiral copper(II) complexes of (S)-phenylalaninamide as additives to the eluent

✍ Scribed by Gianni Galaverna; Francesco Pantò; Arnaldo Dossena; Rosangela Marchelli; Franca Bigi

• Publisher: John Wiley and Sons
• Year: 1995
• Tongue: English
• Weight: 559 KB
• Volume: 7
• Category: Article
• ISSN: 0899-0042
• DOI: 10.1002/chir.530070504

✦ Synopsis

Copper(I1) complexes of 6)-phenylalaninamide have been successfully used for the direct enantiomeric separation of unmodified (R, S)-a-hydroxy acids in reversed phase high-performance liquid chromatography (RP-HPLC). The effect of various parameters (pH, eluent polarity, selector concentration) on enantioselectivity is discussed. Evidence is provided that a mechanism of ligand exchange is actually occurring during the chromatographic separation. The method is very convenient and easy to use, and the chu-a1 selector is commercially available and can be recovered at the end of the analysis. A conventional achiral RP-ODS-2 column is used and no pretreatment of the samples is required. This method allows the accurate determination of the enantiomeric excess of a-hydroxy acids in synthetic and biological samples. o 1995 WiIey-Liss. Inc.