For thousands of years, the fire assay has been the most reliable way of analyzing gold, silver, and platinum group metals. In a fire assay, a small sample of material has its precious metals chemically separated from the impurities and base metals contained in the material. The precious metals remaining are then compared to the original starting weight of the sample to determine the composition percentage. This is a multi-step process which requires a skilled technician to perform. Depending on the material, this can take several hours or several days. So Accurate performs multiple fire assays on each lot to ensure proper results and eliminate errors.
ICP – Induction Coupled Plasma
An ICP is a sophisticated instrument used for detecting trace amounts of metals in a sample. An ICP is sensitive and accurate enough to be able to detect elements down to parts-per-million. In an ICP analysis, a small sub-sample of the material is dissolved in several acids and the resulting liquid is vaporized at very high temperature in a mass spectrometer. Reading the peaks of the mass spectrum output allows the operator to determine which metals are present and at what concentration.
XRF – X-ray Fluorescence
XRF is a non-destructive process in which an item is bombarded with x-rays to determine its composition. These devices “read” the intensity of the x-rays bounced back by the material being tested and can provide a detailed analysis of what elements it is comprised of.