Abstract
A continuous foam separation-extraction-spectro-photometric measurement system has been constructed and evaluated through applying it to the measure-ment of ppb level of Cu (II) ions in water. The flotation conditions were chosen as follows : 0.5 % potassium butylxanthate solution supply rate, 67 ml h-1; 0.075% cetyltrimethylammonium bromide solution supply rate, 114 ml h-1; sample solution supply rate, 1100 ml h-1; pH 9.0; nitrogen gas flow rate, 1000 ml min-1. The foam comming out of the separator is pricked and subsided by the vapor of 1- butanol which was fed continuously through the lower end of the extractor at the flow rate of 19.1 mlh-1.The 1-butanol layer is carried to the flow cell of a spectrophotometer through a Teflon tube at the flow rate of 19.9 ml h-1, which is effected by a peristaltic pump linked behind the flow cell. The extractant which is supposed to be a ternary complex has a characteristic absorbance at 360 nm. Experiments, in which the concentration of Cu (II) in the sample was changed stepwise, showed that it took (3040) min to get a constant absorbance level, that a linear relationship existed between the absorbance and the concentration, and further that minimum concentration to be determined was 3.8 ppb (at S/N=2). Further, experiments where Cu (II) ions were introduced intermittently into the separator showed the constant extraction efficiency. Though it has many points to be improved, it is concluded that the applicability of the proposed system to the determination of low ppb level of Cu (II) ions in water has been confirmed.
