The Fluorometric Determination of Gallium in Aluminum Metal with 8-Quinolinethiol

TLDR: In this paper, a method for the fluorometric determination of gallium in aluminum metal is presented which involves extraction with the methyl isobutyl ketone (MIBK) of the gallium 8-quinolinethiolate complex.

Abstract: A method for the fluorometric determination of gallium in aluminum metal is presented which involves extraction with the methyl isobutyl ketone (MIBK) of the gallium 8-quinolinethiolate complex. The extracted complex has a greenish-yellow fluorescence, with an emission maximum at 505 nm. The maximum fluorescence intensity is obtained at a pH of the initial aqueous phase of around 3.3; the fluorescence remains stable for at least 2 hr. When 50 ml of a sample aqueous solution containing gallium and 0.2 ml of a 0.2% 8-quinolinethiol solution is subjected to extraction with 10 ml of MIBK, the quantity of gallium which can be present for determination in the sample solution amounts to 1 to 30 μg. For the removal of the interfering effects of zinc, cadmium, copper, and nickel on the fluorometric determination, gallium was extracted with isopropyl ether from a 7 M HCl solution. The relative error of this method was 5% for 0.019% gallium in aluminum metal.