Metrological traceability is a fundamental requirement of ISO/IEC 17025:2017, Clause 6.6. It mandates that every measurement result be demonstrably linked to a reference, ultimately to the International System of Units (SI), through an unbroken chain of calibrations, each supported by a stated measurement uncertainty.
In geochemical analysis, traceability is maintained through a structured calibration hierarchy:
– Primary Reference Standards: Certified by recognized Metrology bodies, such as NIST with concentrations directly traceable to the SI.
– Secondary Calibration Solutions: Prepared from primary standards by accredited producers, accompanied by documented uncertainty and a formal traceability certificate.
– Working Standards: Laboratory-prepared dilutions of secondary standards, with all dilution calculations and preparation records fully documented.
– Instrument Calibration: Performed for each analytical batch using working standards. Acceptance is contingent on all calibration points meeting the predefined linearity criteria.
Any disruption to this chain, including the procurement of standards from non-accredited suppliers, use of expired reference materials, or inadequate documentation of dilution procedures, constitutes a traceability gap. Under such circumstances, reported results cannot be considered metrologically traceable.
For exploration and mining companies, the traceability of analytical data supporting resource estimates is a critical component of due diligence. Third-party reviewers and Competent Persons operating under JORC or NI 43-101 frameworks increasingly require verifiable evidence of analytical traceability, beyond the certificate of analysis.
Orelysis provides technical due diligence support to exploration and mining laboratories to ensure compliance with traceability requirements.
Connect with our team of experts at www.orelysis.com
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