SIMULTANEOUS IDENTIFICATION OF SUGARS BY HPLC USING EVAPORATIVE LIGHT-SCATTERING DETECTION (ELSD) AND REFRACTIVE-INDEX DETECTION (RI) - APPLICATION TO PLANT-TISSUES

Two detection systems for sugar HPLC identification, were compared, namely IR and ELSD. Peak separation was carried out on an adapted BECKMAN HPLC chromatographic line with the two detectors in series. This assembly line allowed the superimposition of two detection features on an single chromatogram. The same sugar mixture injection should be identified with both systems in the same conditions. Three separation devices were used. It was demonstrated that the ELSD technique was well adapted for sugar determination. Compared with the RI detection, ESD showed a better sensitivity, more stability of the chromatographic base line and no incidence of the temperature. However, the main advantage of the ESLD system was the assessment of the gradient elution use, since this is excluded in RI detection.