Hplc Enantiomeric Resolution of (+)-Cinchonine and (-)-Cinchonidine With Diode-Laser Polarimetric Detection

Abstract

The combination of UV and diode-laser polarimetric detection of chiral molecules offers significant advantages in high performance liquid chromatography. The method described here circumvents the derivatization step and the use of chiral stationary or mobile phases for the resolution of enantiomers. Data acquisition of the polarimeter was performed with AC/DC interface and software Pic0 ADC-100 coupled to the polarimeter detector. Quantitative methods in the range 1-150 pg and 1-600 pg of (+)-cinchonine and (-)-cinchonidine, respectively, were established. Enantiomeric ratio determined by using UV and diode-laser polarimetric data without chiral separation is discussed.

Resolution of (+)-cinchonine and (−)-cinchonidine by phase-modulation fluorescence spectroscopy

“…Similar linear range and RSD values are obtained with both the modulation and simultaneous equations methods but lower detection limits are obtained with the modulation method. Table 3 also gives data for CN and CD determination by liquid chromatography with photometric-polarimetric detection [6]. It can be observed that a 10 3 -fold diminution in the linear range and detection limits is obtained with the fluorimetric system in comparison with the chromatographic-polarimetric system.…”

“…Analytical characteristics Matrix Proposed method Table 3 Purity of samples HPLC with diode-laser polarimetric detection [6] LD of CN = 0.81 (RSD = 7.5%) g and CD = 0.6 g (16.6%) Pharmaceutical prior derivatization process HPLC with UV detection [26] LD = 2 g mL −1 for each analyte Vegetable sample HPLC with fluorescence detection [22] LD = 100 and 200 fmol Liquid extract and cosmetics HLPC by molecule imprinted polymer [8,10,20] Chiral resolution (Rs = 0.76); monolithic stationary phase (Rs = 5.22) Synthetic samples TLC [11,21,25] Estimation Pharmaceuticals and market formulations Capillary electrophoretic chiral separation of using a cyclodextrin selector [9] Chiral resolution (Rs = 5.59) using [HDM-␤CD] = 7 mM Urine Gas chromatography [23] Identification Cultures Photometry [24] Estimation of circular dichroism Purity of samples chromatographic-polarimetric system were 1.4 and 1.0 mM for CD and CN, respectively. The precision of the measurements is also improved, modulation fluorescence lifetime measurements giving RSD values of 5.2% and 4.0% for CD and CN, respectively, whereas for the chromatographic-polarimetric system the RSD values were 7.5% and 16.6% for CD and CN, respectively Table 4.…”

“…Cinchonine and cinchonidine are Cinchona alkaloids and several methods have been described for the determination of these alkaloids either in crude drug composites, in body fluids or in pharmaceutical formulations [6][7][8]. In this paper, phase-modulation fluorescence spectroscopy has been applied to resolve mixtures of these diasteromeric compounds, and results obtained from two different approaches have been evaluated.…”

Resolution of Deltamethrin, Permethrin, and Cypermethrin Enantiomers by High-Performance Liquid Chromatography with Diode-Laser Polarimetric Detection

“…The instrumental parameters were controlled by Picolog Software (Picotechnology, Cambridge, UK), and the calculation of the area (negative and positive peaks), peak height, and retention time was performed with Lab-Cal LC software (Galactic, Salem, NH). The Picolog program has been described in detail elsewhere (28).…”