Certified Reference Materials (CRM) are the materials that are characterized to an acceptable standard in terms of identification, quantitation of its ingredients. Reliability of results of chemical analysis largely depends on the reference materials used in analysis. Identification can be by comparison of the properties of the reference materials. Many analytical methods need a reference material of known concentration of purity for quantitation purposes.
Neat reference materials are typically assigned a purity factor or potency. This value should include corrections for chromatographic impurities and other residual impurities. The neat material purity factor is important because the analyte mass used in preparation of a solution reference standard from a neat reference material should be corrected for the purity factor of the neat analyte. Certificates of analysis (COAs) for neat reference materials should be carefully examined to ensure that the purity factor assigned was determined appropriately (i.e., that appropriate methods were used to determine chromatographic impurities and that the material was tested for other residual impurities).