CRM Traceability: Not Just an Audit Requirement

Inorganic Ventures is a manufacturer of high-quality Certified Reference Materials (CRMs). We specialize in producing solution standards as both stock and custom products. CRMs are expected to be accurate and perform as expected, but did you know that CRMs are also required to be traceable to the International System of Units (SI)? This traceability establishes a chain of comparisons all the way from the SI to your measurements!

When it comes to establishing CRM traceability the shorter the chain of comparisons the better. This is because each measurement along the chain introduces uncertainty. This uncertainty compounds with each measurement along the chain and can cause your sample measurements to have a higher final uncertainty. At Inorganic Ventures we test our products directly against NIST Standard Reference Materials (SRMs). These SRMs provided by NIST are the closest available standards to the SI base unit of the kilogram for each analyte. This makes CRMs provided by Inorganic Ventures only one step removed from the SI in our unbroken chain of comparisons.

While having a short chain of traceability is ideal, it does not guarantee CRM accuracy. For example, comparing CRMs against a NIST SRM via ICP-OES will not eliminate potential interferences that could cause the comparison to be inaccurate. To guarantee accuracy Inorganic Ventures uses multiple assay methods when certifying our products. Usually, this includes an instrument and titration assay. See the figure below for an example of how we report our traceability through different analysis methods.

Section 3.0 of an Inorganic Ventures Certificate of Analysis (CoA). This product used three separate methods for testing, thus establishing multiple routes of traceability!