Photometric determination of gallium in silicate rocks after separation by crown ether extraction

Abstract

A procedure was developed for the determination of gallium in silicate rocks. It is based on the extraction of gallium by a chloroform solution of a crown ether, 18-crown-6, followed by photometric determination using an improved Rhodamine B method. Gallium was determined in many Geological Survey of Japan rock reference materials. The recovery of gallium in silicate rocks was almost quantitative, with a relative standard deviation of about 2%. The results obtained are within ± 10% of results obtained by other workers.