Reliable assay of extreme enantiomeric purity values by a new circular dichroism based HPLC detection system

Enantioselective cholesteric liquid crystalline membranes characterized using nonchiral HPLC with circular dichroism detection

“…The HPLC-CD method is more versatile than HPLC detection methods that rely on chiral stationary phases because it does not require the use of specific chiral columns for the resolution of different enantiomers. The large spectral range (220-420 nm) [20] of the CD signal enables the detection of a wide variety of enantiomer molecules, and the precision and sensitivity of the nonchiral HPLC-CD detector has been shown to be comparable to chiral HPLC detection systems [13,20].…”

“…flow rate, temperature, concentration, amount injected) it was determined that a wavelength of 260 nm resulted in the highest values for both the CD intensity and the anisotropy factor (Table 1). This ensured that the lowest possible detection limits were achieved [20]. The CD and UV peaks of 1-phenylethanol were appeared at a retention time of 7 min while monitoring at a wavelength of 260 nm (Fig.…”

High-throughput comprehensive analysis of d- and l-amino acids using ultra-high performance liquid chromatography with a circular dichroism (CD) detector and its application to food samples

“…The regression coefficients were above 0.99 for all amino acids. d-Form ratio (d/(d + l)) was determined by the g-factor (= ε/ε) which was calculated from UV (ε) and CD ( ε) signals [32,37,38]. CD signals from the CD detector (X-LC 3195CD) were converted to degree order: g-facor (deg/AU) was calculated as follows (g-factor = CDsig × 4/2.303 × /180/AUsig).…”

Achiral liquid chromatography with circular dichroism detection for the determination of carnitine enantiomers in dietary supplements and pharmaceutical formulations

“…The g factor was found to be proportional to the enantiomeric excess but is independent of concentration [31]. Many authors [32][33][34][35][36] have already demonstrated that this detector, coupled with an achiral stationary phase, was suitable to determine 99.8-98% enantiomeric excess values (0.1-2% enantiomeric purity). Nevertheless, any method has been applied to dietary supplements and pharmaceutical formulations so far.…”