关键要点
- Accreditation applies to named methods, not to the laboratory generally.
- Contract results should come from an accredited scope where possible.
- Method choice must match the decision the result will support.
Scope matters
A laboratory accredited for proximate analysis is not thereby accredited for mycotoxins or heavy metals. Check that the specific method for the specific matrix appears in the accreditation schedule before relying on a result contractually.
Reproducibility between laboratories
Two competent laboratories using the same method produce results within a defined reproducibility range. Contract tolerances should account for that range, otherwise routine analytical variation generates avoidable disputes.
需要核查的内容
- Method and matrix listed within the laboratory's accreditation scope
- Contract naming the analytical method for each parameter
- Tolerances accounting for method reproducibility
需管理的风险
- Disputes generated by method differences rather than product differences
- Screening results treated as contractual results
- Results reported outside the laboratory's accredited scope
常见错误
- Assuming accreditation covers everything the laboratory offers
- Comparing results produced by different methods
- Setting tolerances tighter than method reproducibility
常见问题
Are rapid methods acceptable?
For screening and process decisions, yes when properly calibrated. Contractual and dispute results normally require the reference method named in the specification.
Why do two laboratories disagree?
Usually sampling differences or method differences, and normal reproducibility variation. This is why the sampling protocol and named methods belong in the contract.