Speciation of selenium and arsenic compounds in natural waters by capillary zone electrophoresis after on-column preconcentration with field-amplified injection

Abstract

A method for the separation and determination of selenium and arsenic compounds by capillary zone electrophoresis (CZE) was developed. On-column enrichment of selenium and arsenic was performed by stacking large volumes of samples injected onto the column with the field-amplified injection technique. Over a 100-fold preconcentration for selenium and arsenic compounds could be achieved within 3.7 min. This method was applied to the determination of selenium and arsenic species in real water samples. The detection limits were below 25 ppb. The relative standard deviations for the determination of selenium and arsenic species in water samples were in the range 4.0 to 15.6%.