SURFACE-PLASMON RESONANCE-BASED DETECTION - AN ALTERNATIVE TO REFRACTIVE-INDEX DETECTION IN HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

The surface plasmon resonance (SPR) effect was exploited to develop a detector responding to changes in the refractive index for use in high -performance liquid chromatography. The performance of the SPR detecto r was compared with that of a refractive index (RI) detector from Hewl ett-Packard. The effects of the optical fibre connections and light-em itting diode wavelengths (1300 and 850 nm) were studied. The detectors that were tested provided similar limits of detection for the sugars, fructose (7 mu g for RI and 5 mu g for SPR), glucose (7 mu g for RI a nd 13 mu g for SPR) and sucrose (13 mu g for RI and 22 mu g for SPR). The SPR was found to reach a stable baseline quicker than the RI detec tor, i.e., 50 min before the RI detector did.