Se. Ghazy et Ma. Kabil, DETERMINATION OF TRACE COPPER IN NATURAL-WATERS AFTER SELECTIVE SEPARATION BY FLOTATION, Bulletin of the Chemical Society of Japan, 67(8), 1994, pp. 2098-2102
Microgram amounts of copper(II) in one liter of water are quantitative
ly separated selectively as copper(II) acetate with oleic acid surfact
ant at pH range 6.5-7.5. The floated scum is separated, after shaking
for few seconds, and measured colorimetrically at 700 nm. Beer's law i
s obeyed in the concentration range (0.5-5)x10(-4) mol dm-3, {3.18-31.
8 ppm of copper(II)}. Alternatively, the copper in the scum is eluted
by nitric acid 0.1 mol dm-3, completed to the suitable volume required
for copper atomic absorption measurement at 324.7 nm with 1 ppm detec
tion limit. The different factors affecting the selective flotation of
copper(II) have been studied. It has been found that iron(III) seriou
sly depresses the flotation efficiency. The flotation mechanism is dis
cussed. The method of the separation and determination is rapid and ap
plicable to 50 ppb copper(II) concentration level in natural waters.