Capillary zone electrophoresis with indirect photometric detection in the visible range

Sensitivity and applicability of commonly used indirect photometric detection in the UV region can be adversely affected by the absorption of the UV light by detected solutes and/or by matrix constituents migrating with them. If the visible light is exploited instead of the UV light, both these disadvantages may be for the most part eliminated, and, moreover, the indirect photometric detection will extend its versatility and sensitivity. Prospects as well as main problems of the approach 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 background 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.