1988 Volume 4 Issue 4 Pages 417-421
The trace amounts of gallium and indium in water were determined by graphite furnace atomic absorption spectrometry after being concentrated by the coprecipitation technique with hafnium hydroxide. Hafnium hydroxide coprecipitates quantitatively 0.2-3μg of gallium from 50-400ml of sample solution at pH 6.0-10.5 and 0.2-4μg of indium from 50-400ml at pH 6.0-11.0. The atomic absorbances of gallium and indium are increased about 3 times by the presence of hafnium; the reproducibilities of the measurements are also improved. The calibration curve is linear from 8 to 120ng ml-1of gallium or from 8 to 160ng ml-1of indium. Twenty seven diverse ions tested did not interfere seriously with either element. These methods are applicable to the determination of gallium and indium in river or seawater which contains down to 0.5ng ml-1of these elements.
