Anion exchange separation and spectrophotometric determination of aluminum and copper in solder alloys

A method of spectrophotometric determination of Al and Cu after their anion exchange separation has been presented, by which trace amounts of Al and Cu in solder alloys have been determined with satisfactory results. A medium of 65% ethanol-2.5 M hydrochloric acid is employed for the quantitative separation of microgram amounts of Al from large quantities of Sn, Pb, by means of ion exchange using a strongly basic anion exchanger, Diaion SA # 100(100200 mesh, Cl-form). From this hydrochloric acid-ethanol medium, is adsorbed no Al on the resin whereas Sn, Pb and Cu. are completely adsorbed, so that a quantitative removal, of these elements from Al can be easily effected and then aluminum can be determined spectrophotometrically by Chromazurol S method. Copper was easily eluted with 2 M hydrochloric acid and was determined spectrophotometrically by biscyclohexanone oxalyldihydrazone method. Similarly minute quantities of Al in tin, zinc and lead-base white metals were determined after chromatographic removal of large amounts of Pb, Sn, Cu, Sb and Zn.