Skip to the main content.


Expert-Approved OES Analyzers for High Purity Metal Impurities from Metal Analysis Group


The purity of precious metals is a critical factor in determining their monetary value. Accurate determination of precious metal content is essential when trading these metals or their products. For high-purity gold and platinum, contents of up to 99% are determined using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) following the bracketing method (EN ISO 11494, 11495). This method calculates the purity of these metals by measuring impurities and subtracting them from the total, as outlined in ISO standard 15093.

ICP-OES is ideal for analyzing impurities in precious metals due to its multi-element capability, large linear dynamic range, and high sensitivity. This method provides precise detection of trace elements, ensuring accurate determination of contamination in high-purity gold and platinum.

Optical Emission Spectroscopy (OES) is a widely used analytical technique for determining the elemental composition of various metal alloys. By exciting atoms in a sample to a high-energy state using a spark or arc and then measuring the emitted light as these atoms return to lower energy states, OES can accurately determine the concentration of elements within the sample. This precision is critical in metallurgy, where understanding the exact composition of alloys ensures material quality and performance.

The use of high-purity gas in OES is essential. Impurities in the gas can lead to inaccurate readings or interference in the emission spectra. High-purity gas provides a stable and consistent environment for the plasma, ensuring that the emission lines from the sample are not contaminated or altered. This stability is crucial for achieving the high levels of accuracy and precision required in OES analysis. The purity of the gas affects the quality of test results, the reliability, and the repeatability of measurements, which are critical factors in quality control and material certification processes.

High-purity gas in OES minimizes background noise and enhances the sensitivity of detection. Impurities can generate their own emission lines or alter the intensity of the sample’s lines, leading to erroneous conclusions about the sample’s composition. Using high-purity gas ensures that the light emitted from the sample is as clear and unobstructed as possible, allowing for more precise measurements. This precision is especially important in applications requiring accurate determination of trace elements, such as in the aerospace, oilfield, recycling, and automotive industries.

The PerkinElmer Avio 550 Max ICP-OES has demonstrated its capability to analyze solutions of 1% nickel for elements at the levels defined by the London Metal Exchange. It effectively mitigates the effects of spectral interferences from high matrix samples, enabling accurate measurement of all specified elements at their defined concentrations