Determination of Sub-ppm Levels of Silver in Heat-Resisting Alloys by Graphite Furnace Atomic Absorption Spectrometry

Abstract

A rapid and simple analytical method has been developed for the determination of sub-ppm levels of Ag in Ni- and Co-base heat-resisting alloys by graphite furnace atomic absorption spectrometry. Nickel or Co, a base element of heat-resisting alloys, did not affect the absorbance of Ag. The effects of the other elements and acids on the absorbance of Ag were also studied. As a result, the acid solutions of Ag were used as the calibration solutions for the determination of sub-ppm levels of Ag in complex heat-resisting alloys. The results obtained by the calibration curve method agreed well with those by the standard addition method. The detection limit of Ag was 0.005 ppm in the sample by the method described. This method, however, can not be applied for the determination of Ag in Co-base heat-resisting alloys containing large quantities of Al and Ti because of the interferences.