Indirect photometric detection of anions in capillary electrophoresis

Abstract

Indirect photometric detection (absorbance and fluorescence) of anions by capillary electrophoresis is reviewed. Factors which influence the displacement process of analyte ions in background electrolytes containing one or more co-ions are discussed and factors which influence detection sensitivity in indirect detection modes are outlined. Procedures are presented for buffering background electrolytes when indirect absorbance detection is to be used in the determination of anions, and approaches to the design and optimization of the composition of background electrolytes for indirect detection of anions are discussed. The application of indirect detection to the separation of major groups of analytes including inorganic anions, organic acids, carbohydrates, phosphates, phosphonates and miscellaneous species is then reviewed. Detailed information on the physical properties of species used as probes for indirect detection of anions is provided.