ISO/IEC 17025:2017 distinguishes between method validation and method verification, and the distinction determines how much experimental work a laboratory must do before using a method.
Method validation:
– Required when a laboratory develops a new method or significantly modifies a standard method.
– Full validation involves: establishing working range, linearity, detection limits, precision (repeatability + reproducibility), accuracy (bias vs CRM), matrix effects, and ruggedness.
– Result: a documented validation report with performance characteristics for defined matrices and concentration ranges.
Method verification:
– Required when a laboratory adopts an externally published standard method (ISO, ASTM, AOAC, etc.) without modification.
– Verifies that the laboratory can achieve the performance parameters claimed in the standard under its own conditions.
– Typically involves: CRM analysis to confirm accuracy, replicate analysis to confirm precision, and demonstration that DL meets the standard’s specification.
– Scope is narrower than full validation — it confirms fitness for purpose, not full characterisation.
A common error is laboratories treating verification as optional when adopting a published method. ISO 17025 clause 7.2.2 is explicit — verification is mandatory. Accreditation bodies will audit for verification records.
Both processes must be documented, reviewed, and updated when conditions change — such as a new instrument, a new reagent lot, a new operator, or a new matrix type.
For technical
questions or further discussions on geoscience applications, Orelysis’ expert team at Orelysis.com is available for consultation.
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