Optimization of capillary electrophoresis method for the determination of rare earth elements in soils and natural waters

Currently, rare earth elements (REEs) in the environmental objects are determined by neutron activation and ICP-MS methods. Capillary electrophoresis (CE) is not used for these purposes because the poor detection limits (LOD). This weakness can be overcome by multiple concentrating of the samples through the high effective sample stacking process of triply charged ions Ln3 +. LOD for REEs were received ranged from 0.2 to 1.2 μg/l. The following composition of background electrolyte for CE determination of lanthanides was proposed: 12 mM benzimidazole, 8 mM dipropylglycolic acid, 10 mM glycolic acid, pH = 3.0. Using this background electrolyte the completely separation of REEs (Y + La + Ln without Pm) is possible for 12 min. The sample preparation procedure for CE determination of lanthanides in soil and natural water was improved and the analysis of these analytes was performed. The validity of experimental results was confirmed by AES and ICP-AES methods.