UNIVERSAL DETECTOR BASED ON MAGNETOOPTICAL ROTATION FOR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

Magnetooptical rotation (MOR) or the Faraday effect in the absence of absorption is a general physical property for all substances and can be used for universal detection in high-performance liquid chromatography. The longitudinal magnetic field with moderate field strength is provided by a cheap and compact permanent magnet assembly. A simplified equation has been derived for calculating Verdet constants of mixtures. The experimental results confirm the linear relationship between the MOR signal and weight fraction of the solute in dilute solution. The linear range is limited by the artifact signals caused by the refractive index change at high concentrations. The feasibility of this method is demonstrated in the detection of polynuclear aromatic hydrocarbons, where the limit of detection is in the submicrogram range.