HIGHLY LITHIUM-SELECTIVE CROWN ETHER DYES FOR EXTRACTION PHOTOMETRY

Abstract

Abstract Lipophilic 14-crown-4 derivatives bearing a chromogen such as nitrophenol and azophenol residues prove to be excellent extraction-photometric reagents for lithium ion. The lithium selectivities are extremely high, the extraction equilibrium constants for lithium being increased about two orders of magnitude over those for sodium.