ABSTRACT

Polarimetric detection offers numerous benefits to supercritical fluid chromatography (SFC) applications. Laser polarimeters operating at 670 nm only respond to optical activity and ignore absorbance-all peaks are enantiomers or optically active and gradients do not affect the baseline. Detection is based on polarization (phase) changes, not absorbance (amplitude) changes. Polarimeters respond to enantiomers with a unique positive or negative peak with amplitude proportional to concentration and specific rotation-regardless of elution order or separation method. In analytical applications, polarimeters show peaks with optical activity, even when analytes lack a chromophore. In method development applications,

polarimeters show elution order of enantiomers and confirm that peaks are enantiomers. In preparatory applications, polarimeters control peak collection based on peak polarity rather than just slope and do not suffer from the overload and non-linear problems of absorbance-based detectors (if too much light is absorbed, there is nothing left to detect).