MICELLAR SOLUBILIZATION PHOTOMETRIC DETERMINATION OF MICROAMOUNTS OF COPPER IN DRINKS WITH DDTC IN THE PRESENCE OF TWEEN 80

In an ammoniacal buffer of pH 10,the coordination reaction of Cu(Ⅱ) with DDTC was solubilized by the addition of Tween 80,and the photometric measurements were made directly in the aqueous solution at the wavelength of 442 nm.Where the apparent molar absorptivity was found to be 1.32×103L·mol-1·cm-1.Beer′s law was obeyed in the concentration range of 0.028-4.70 mg of Cu per L of solution,with a detection limit of 0.01 mg·L-1.This method has been used in the determination of copper in 5 kinds of drink samples,giving RSD′s in the range of 1.04%-1.63% and recoveries in the range of 96.5%-101.7%.And also the results obtained by this method were in consistency with those found by the DDTC-CCl4 extraction photometric method.