DIRECT SEPARATION OF CARBOXYLIC-ACID ENANTIOMERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH AMIDE AND UREA DERIVATIVES BONDED TO SILICA-GEL AS CHIRAL STATIONARY PHASES
N. Oi et al., DIRECT SEPARATION OF CARBOXYLIC-ACID ENANTIOMERS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH AMIDE AND UREA DERIVATIVES BONDED TO SILICA-GEL AS CHIRAL STATIONARY PHASES, Journal of chromatography, 689(2), 1995, pp. 195-201
For the separation of carboxylic acid enantiomers by HPLC, the chromat
ographic properties of four chiral amide and urea derivatives [N-3,5-d
initrobenzoy1-D-1-(a:-naphthyl)glycine, 3,5-dinitrophenylaminocarbonyl
-D-phenylglycine, 3,5-dinitrophenylaminocarbonyl-L-valine and 3,5-dini
trophenylaminocarbonyl-L-tert.-leucine] covalently bonded to 3-aminopr
opylsilanized silica gel as chiral stationary phases were examined. Di
rect separation of various carboxylic acid enantiomers was accomplishe
d with these chiral stationary phases. The influence of the compositio
n of the mobile phase in these enantiomer separations was shown. Amino
acid enantiomers were also well resolved in the form of their derivat
ives containing a free carboxylic acid group, such as tert.-butoxycarb
onyl (t-BOC), benzyloxycarbonyl (Z), 9-fluorenylmethoxycarbonyl (FMOC)
and 5-dimethylamino-1-naphthalenesulfanyl (dansyl) derivatives.