CAPILLARY ZONE ELECTROPHORESIS WITH INDIRECT PHOTOMETRIC DETECTION INTHE VISIBLE RANGE

Sensitivity and applicability of commonly used indirect photometric de tection in the UV region can be adversely affected by the absorption o f the UV light by detected solutes and/or by matrix constituents migra ting with them. If the visible light is exploited instead of the UV li ght, both these disadvantages may be for the most part eliminated, and , moreover, the indirect photometric detection will extend its versati lity and sensitivity. Prospects as well as main problems of the approa ch were tested using inorganic ions as analytes. If organic dyes with a molar light absorption coefficient of the order of 10(6) mol(-1) L m (-1) was selected as the light-absorbing constituents of the backgroun d electrolyte, detection sensitivity comparable with the best reported results was reached for anions; for cations, the detection limit was even lower by two orders of magnitude.