Design and adaptation of an interface for commercial capillary electrophoresis-evaporative light scattering detection...

In this technical note, an interface for coupling commercially available capillary electrophoresis (CE) equipment to an evaporative light scattering detector (ELSD) is described. The nebulization process was identified as the most critical parameter for performing the reliable coupling between both pieces of equipment. Therefore, appropriate modifications in the nebulization chamber and in the conventional nebulizer were brought to make ELSD fully compatible with CE. The impact of the customized interface on CE separation and detection was evaluated in terms of resolution and sensitivity. ELSD can be considered as an attractive alternative to other CE detection systems (e.g., UV-vis, fluorescence, electrochemical detection, or even MS detection), particularly those in which derivatization is needed. This advantage is due to the versatility and the quasi-universality of ELSD. Thus, sensitive and fast separations of several compounds were performed using this CE-ELSD customized arrangement, which opens up an interesting analytical potential for the determination of compounds not presenting sensitive UV-vis chormophore, fluorophore, or electroactive groups. Carbohydrates were selected in this work to demonstrate the applicability of CE-ELSD coupling.