Spectrophotometric Determination of Trace Copper in Dental –Unit Waste Water Using the Reagent (3, 5-Dibromo-2-Pyridylazo)-N-Ethyl-N-(3- Sulphopropyl) Aniline (3, 5-Di-Br-PAESA)

A simple and low cost method been utilized for the tenaciousness of trace copper ions in dental – unit
wastewater samples. The method is predicated on the reaction of copper ions with the reagent 4-(3,5-dibromo-2-
pyridylazo)-N-Ethyl-N-(3-sulphopropyl) aniline (3,5-di-Br-PAESA) in acidic medium .The composed intricate shows an
absorption maximum at 580nm at max was obtained employing acidic buffer for intricate reaction to take place. Plots of
the colored Cu –reagent intricate were obeyed in the concentration range 6.25-50ug/ml-1copper ions, respectively with a
relative standard deviation in the range of 2±1 %. The inhibition of the detection (LOD) and quantitation (LOQ) of the
procedure were 0.02 and 0.1ng/ml-1 Cu2+respectively. The proposed method was applied for the analysis of copper in
dental-unit wastewater samples.