Ultraviolet spectrophotometric determination of copper in copper ores by flow-injection analysis

摘要

A flow-injection analysis (FIA) method for the ultraviolet spectrophotometric determination of copper in copper ores is described. The ore samples are dissolved in concentrated perchloric acid, the excess acid is neutralized with ammonia solution, andthe resulting solution is used for the determination of copper. The UV-FIA system is based on the reaction of copper (II) ions with pyrophosphate and subsequent measurement of the absorbance of the dipyrophosphatocuprate (II) complex at 240 nm. The mainfactors which control the formation of this complex and the FIA variables influencing the system are discussed. The calibration graph is linear from 2-50 ppm copper. At a sampling rate of about 70 samples h~(-1) with 50 μ1 sample injections, precisionwas about 1% relative standard deviation. Results obtained compare well with those obtained by atomic absorption spectrometry.