Spectraphotometric Determination of Copper in Copper Ores with 1-(2,6-dibromo-4-nitrophenyl)-3-(4-nitrophenyl)-Triazene

A method for spectraphotometric determination of copper in copper ores with 1 (2,6 dibromo 4 nitrophenyl) 3 (4 nitrophenyl) Triazene is reported in this paper. In the presence of Triton X 100 and in pH =9.5～11.5 Na 2B 4O 7 NaOH buffer solution, copper (Ⅱ) reacts with 1 (2,6 dibromo 4 nitrophenyl) 3 (4 nitrophenyl) Triazene and forms a 1∶1 yellow complex. The maximum molar absorbance is 1.11×10 5 L·mol -1 ·cm -1 .The dual wavelength spectrophotometry is used in this work, in which the reference and determination waves are 535 nm and 450 nm respectively. Beer's law is obeyed in the concentration range of 0～360?μg/L for copper (Ⅱ). The method has been applied to the determination of copper in copper ores. The results are in agreement with those determined by AAS and the precision of determination for BY2170 1 aluminum alloy sample with w (Cu)=0.11% is 3.4% RSD ( n =10).