Chiral polymeric reagents for off-line and on-line derivatizations of enantiomers in high-performance liquid chromatography with ultraviolet and fluorescence detection: an enantiomer recognition approach.
Optically active and detector-sensitive polymeric reagents have been synthesized, loadings determined, derivatizations/separations/detection optimized, and applications to simple amines and amino alcohols described. Such reagents have been designed to contain different chiral centers, usually amino acids, leashed via an activated ester attachment to an insoluble, structurally rigid, organic polymer backbone. 9-Fluorenylmethyl (FMOC) moieties chemically bonded to the amino acids were used as ultraviolet (UV) and fluorescence (FL) sensitive detector probes to the final diastereomers of enantiomer substrates. Such diastereomers can be readily separated by isocratic or gradient elution normal-phase methods. The kinetics for diastereomer formation have been determined, and final UV/FL responses for known mixtures of enantiomers have been compared to demonstrate overall validity of the method. Minimum detection limits, linearity of calibration plots, dual detector responses, and linear diode array spectra and absorbance ratios have also been demonstrated. In some cases, authentic standards have been prepared to calculate absolute percent derivatizations for specific enantiomer pairs. The overall approach permits, for the very first time, off-line or on-line precolumn derivatization for the formation of diastereomers having unique detector properties. It has been proven that the rates and rate constants for such formations are identical for at least those pairs of enantiomers studied. Separations are base-line or near-base-line, permitting accurate and precise quantitative determinations, by both UV and FL, of enantiomer/optical purity and chemical purity.
T Y
TY
Chou
C X
CX
Gao
N
N
Grinberg
I S
IS
Krull
D055598:Chemical Phenomena; D002621:Chemistry; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism