Study on the Extraction and Color Reaction of Cobalt(II)and Copper(II) by PEG 2000-Na_2SO_4-XO System

摘要

The extraction and color reaction and reaction mechanism of cobalt(II)and copper(II)were investigated in polyethylene glycol(PEG)-sodium sulfate(Na_2SO_4)-xylenol orange(XO) bi-aqueous phase system .The results shoow that cobalt(II)and copper(II)can be quantitatively ext racted into PEG 2000 phase at pH 5.5-6.5 sodium acetate-acetic acid buffer solution and a new without usual organic solvent extraction method fro determination of mircro amounts of cobalt(II)and copper(II)is advanced. Comparing to a general water sphase spectrophotometry, the new method has advantage of maximum wavelength of complex shifted to the red wavelength, molar ratio of metal ion to reagent increased, sensitivity, and selectivity of method increased .This method was used to determine micro amount of copper(II)in aluminium alloy and micro amount of cobalt(II)in Vitamin B_(12)with satisfactory results