Abstract
A method has been described for the ionexchange and photometric determination of microgram quantities of copper in alkali industry.
Sample of the alkali products such as soda ash and caustic soda was acidified with 12N HCl and the pH value was adjusted to 35. This solution was passed through the Dowex A-1 resin column at the rate of about 6 ml per min. Copper was then eluted from the column with 2N HCl and the effluents were gathered in a separatory funnel, to which were added 10 ml of the combined reducing reagent (NH2OH·HCl+Na-citrate) and NH4OH to adjust the pH 46. 5ml of 0.1% neocuproine were added and the resulted brownish complex was extracted with exactly 10 ml of CHCl3. The absorbancy was measured with a spectrophotometer at 460 mμ.
Copper in alkali products was determined accurately by this method, the time required for a determination being about four hours.
