Retention Selectivity between 4-(2-Pyridylazo)resorcinol and Its Cobalt Chelate in the Solid Phase Extraction Systems and Its Application to the On-Line Preconcentration for Reversed Phase HPLC

摘要

Preferential solid phase extraction of ultratrace metal chelate from the excess of its ligand has been succeeded in the case of cobalt,4-(2-pyridylazo)resorcinol (PAR),ODS-Silica,and H_2O system,applying the reverse order of them found in reversed-phase HPLC wiht aqueous methanol and ODS-SiO_2.This finding makes it possible to concentrate the 1-ppt level of cobalt chelate in the presence of excess PAR from aqueous samples using kinetically selective HPLC.