A USEFUL UV SPECTROSCOPIC METHOD FOR THE DETERMINATION OF THE CONCENTRATION OF DIETHYLENETRIAMINE (DETA) IN AQUEOUS MINERAL FLOTATION SOLUTIONS

An alternative method for the determination of the concentration of di ethylenetriamine (DETA) in aqueous mineral flotation solutions is desc ribed. This method is based on the formation of a DETA-Ni(II)-sulphite complex, which shows a UV absorption maximum at 285 nm that varies li nearly with the concentration of DETA throughout the 0-50 mg l(-1) DET A range. A high concentration of Ni(II) is used to offset the effect o f any Cu(II) or Ni(II) ions that may already be present in the industr ial plant solutions under analysis. The intensity of the absorbance ma ximum is dependent on the sulphite ion concentration, but this problem is overcome by measuring the absorbances when the test solutions are spiked with different concentrations of DETA and then extrapolating th e absorbance versus DETA concentration plot to zero absorbance to obta in the original concentration of DETA in the test solutions. (C) 1998 Elsevier Science B.V. All rights reserved.