Application Brief

High Precision Determination of Major Precious Metal Components Using ICP-OES and the Bracketing Technique

Usually, ICP-OES is used for the determination of minor and trace elements. If main components need to be determined, a strong focus is placed on the precision of the measurement. Particularly in the research of modern materials, a very precise analysis is increasingly required because the stoichiometric composition of alloys influences the properties of a material. In the jewelry industry, an exact analysis has been a requirement for a long time. The precious metals content is the main factor for their monetary value. Therefore, it needs to be most accurately determined when trading precious metals or precious metal products.

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) can be used perfectly for the precise determination of major compounds. A special technique for high-precision measurements has been developed by the precious metals industry for the determination of the composition of jewelry alloys. This bracketing technique is described in the ISO standards 11494 and 11495. The bracketing principle can also be used for the analysis of other major compounds in general, where high precision and accuracy is required. The following report describes the basic approach of analyzing major compounds according to ISO 11495, as well as the implementation of the bracketing technique using the ICP Analyzer Pro software.