[Spectrophotometric determination of trace copper in electroplating wastewater]

In the presence of CPB and OP, the chromogenic reaction of DBH-PF with Cu(II) was studied. The results show that the purple micelle reaction has high sensitivity in the medium of (CH2)6N4-HCl(pH = 5.4) buffered solution, the molar absorptivity is 1.8 x 10(5) L.mol-1.cm-1, and Beer's law is obeyed for Cu(II) in the range of 0.0-9.0 micrograms.25 mL-1 at 540 nm. Combined with solvent extraction separation, the method has been applied to the determination of trace Cu in electroplating wastewater with satisfactory results.