Analysis of milligram amounts of aluminum bronze by ICP-AES with an internal-standard method.

Abstract

In order to accurately determine major elements (Cu, Al, Fe, Ni and Mn) in milligram amounts of aluminum bronze reference samples, an application of ICP-AES using scandium as an internal-standard element was investigated. The correlation coefficient of the emission intensities of each major element to scandium was above 0.95, and the repeatable precision in measuring the emission intensity ratio of each major element to scandium was 0.11∼0.43% (RSD, %, n=25), which corresponded to 1/2∼1/6 times that obtained without an internal standard. In an analysis with a 10 mg or a 5 mg amount of the sample, the relative variances for 5 major elements {Relative variance (%)=[(Mfound)-(Mcert)/Mcert]×100, where Mfound and Mcert are the found and certified values, respectively}. were -3.1∼+4.4%, except for Mn, whose content in the sample was under 1%. Based on these results, the proposed method will offer an advantage of improving the precision and accuracy in the analysis of milligram amounts of aluminum bronze samples.