HPLC Optical Rotation Detector (ORD)

Specific for the optical isomer measurement. The column can separate R- and L- type optical isomers, but the general detectors (e.g., UV) cannot distinguish which is R nor L. OR detector provides this information.

In chiral chromatography, the technology of detecting chiral molecules using optical devices has lagged behind until now. The stability and sensitivity of this type of instrument is an important issue in chiral chromatography. However, with the availability of the single wavelength LED, increased sensitivity and increased economics with simplified instrument design was possible. In addition, a newly designed glass coated steel flow cell has produced a superior, third generation optical rotation detector. Aided with the Faraday compensation technique, this instrument gives high optical rotation power with excellent signal to noise ratio. This instrument is an excellent supplemental detector to standard UV detection. For chiral separations, it permits the identification of elutionorder which is important when quantifying to establish minimum levels of detection. It allows for the identification of enantiomeric pairs when dealing with multiple chiral centers. During the method development process, this detector detects marginal selectivity when UV detection fails. The important features of this instrument will be described. Also, examples of absolute sensitivity, identification of enantiomer pairs and reversed elution order will be included.

  • Identifies the chirality of a molecule with a positive or negative sign of rotation.
  • Detects only optically active compounds.
  • Can detect optically active compounds with no or low UV absorbance.
  • Works with gradients.
  • Simple determination of enantiomeric excess (ee) and optical purity.

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