Cationic diazacrown ethers as selectors for the separation of inorganic anions by capillary electrophoresis

Two types of positively charged diazacrown ether derivatives involving two quaternary ammonium ions in the 12- and 18-membered rings have been investigated as selectors for the separation of inorganic anions by capillary electrophoresis. Both the cationic macrocycles largely affected the electrophoretic mobilities of analyte anions, and a group of seven inorganic anions examined in this study was completely separated in less than 2.2 min by the use of the low concentration of the additives. From the determination of ion association constants, the cationic diazacrowns were found to show greater electrostatic interaction with divalent anions than with monovalent ones.