Identity
Does the selected procedure distinguish the stated material from plausible alternatives? Confirm the claim, reference comparison, acceptance logic, and limits of discrimination.
Start with the boundary
A COA is a claim set, not a conclusion.
A certificate records what its issuer reports about a submitted sample under stated conditions. It does not automatically establish independent sampling, custody, lot representativeness, or fitness for your laboratory’s intended work.
Procurement rule: resolve identity and lot mismatches before interpreting analytical numbers.
Three fields that must stay separate
- Specification
- The acceptance criterion or target, with units and comparison rule.
- Measured result
- The observed value or qualitative finding produced by the stated procedure.
- Disposition
- The issuer’s stated interpretation, such as pass, fail, released, draft, or superseded.
Twelve-point review
Verify the record before relying on the result.
Mark each item complete, unresolved, or not applicable. Preserve the reviewed file and the date of review.
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Document identity
- Title identifies the file as a certificate or report.
- Unique report or certificate number is present.
- Page count, revision, and attachment references are consistent.
- Issuer, signature or authorization, and status are visible.
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Supplier and laboratory identity
- Supplier and testing laboratory are named separately.
- Laboratory address and direct contact path are verifiable.
- Commissioning party and report recipient are identified.
- Any accreditation claim is checked against current scope.
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Product identity
- Material name and unambiguous identifier agree across records.
- Form, salt/counterion, or other stated material descriptor matches.
- Identity procedure is named and suited to the stated claim.
- Names and identifiers do not conflict between pages.
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Lot or batch match
- COA lot/batch exactly matches label and procurement record.
- Formatting differences are explained, not assumed.
- Repackaging or relabeling links retain a documented parent lot.
- QR code or portal lookup resolves to the same lot and revision.
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SKU and stated amount
- SKU or catalog identifier matches the material offered.
- Stated amount and unit match label and procurement record.
- Amount claim is not inferred from chromatographic purity.
- Package count and unit-level identifiers are reconciled.
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Specification versus result
- Acceptance criterion and observed result use separate fields.
- Units, basis, comparison operator, and reporting convention appear.
- Pass/fail statement follows the displayed criterion.
- Rounding or uncertainty does not reverse the stated disposition.
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Method scope
- Method name, identifier, revision, and key detection mode appear.
- Procedure purpose is stated: identity, purity, assay, impurity, or other.
- Validation or verification is relevant to the matrix and range.
- Specificity/selectivity and system suitability are addressed where applicable.
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Chromatogram or spectrum availability
- Complete supporting output is available or its absence is recorded.
- Sample ID, file/run ID, axes, units, and acquisition time are legible.
- Peak assignments and integrations are not cropped or unexplained.
- Supporting output maps to the reported sample and result.
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Purity, identity, and quantity distinction
- Each claim is tied to its own procedure and result.
- Area percent is not relabeled as identity or net amount.
- An identity signal is not relabeled as a quantitative assay.
- Orthogonal evidence is requested when the claim requires it.
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Dates, version, and status
- Receipt, analysis, issue, and any reissue dates follow a coherent sequence.
- Draft, final, corrected, superseded, or withdrawn status is explicit.
- Current revision replaces older copies without silent changes.
- Any validity or retest statement includes its stated basis.
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Custody and provenance limits
- Sample submitter, selector, and sampling point are known.
- Seal condition, receipt state, and custody transfers are documented when claimed.
- Relationship between submitted sample and delivered lot is supported.
- “Third-party” is not treated as blind or independent sampling without evidence.
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Decision record
- Unresolved questions are sent through a verifiable contact path.
- Original file, portal response, and correspondence are retained.
- Reviewer, date, outcome, and rationale are recorded.
- Material remains on hold when critical mismatches are unresolved.
HPLC boundary: an HPLC result supports only the claim justified by the stated procedure, detector, standards, calculations, and validation scope. HPLC alone does not establish identity, net quantity, sterility, or endotoxin status.
Interpretation guide
Ask what each procedure was designed to show.
Purity / impurities
What components can the procedure detect and separate under the stated conditions? Confirm integration rules, excluded peaks, reporting threshold, and calculation basis.
Quantity / assay
What amount or concentration is being estimated, against what standard, and over what range? Confirm units, reference value, calibration model, and uncertainty or reporting convention.
Stop and clarify
Red flags that limit reliance
- Lot, SKU, amount, or material name does not match.
- Report number, authorization, revision, or final status is missing.
- Supplier and laboratory appear interchangeable or cannot be verified.
- Accreditation logo appears without a verifiable certificate and relevant scope.
- A specification is presented as though it were the measured result.
- Result lacks units, method identifier, or acceptance criterion.
- Purity area percent is used as identity or net-amount evidence.
- Chromatogram or spectrum is cropped, unreadable, or tied to another sample.
- Dates are impossible, out of sequence, or silently altered between copies.
- “Third-party tested” appears without sample-selection or custody detail.
- Portal or QR lookup resolves to a different lot, file, or revision.
- Issuer will not confirm the report through an independently found contact path.
Close the review
Choose and document an outcome.
Review record
Material / SKU / stated amount
Lot or batch
Certificate / revision / status
Reviewer / date
Outcome / rationale
Evidence base
Authoritative references
- ICH Q2(R2), Validation of Analytical Procedures — intended purpose and performance characteristics for identity, purity, impurity, assay, and related procedures.
- ISO/IEC 17025, Testing and calibration laboratories — laboratory competence and confidence in results.
- ISO 33401:2024, Reference materials — Contents of certificates, labels and accompanying documentation — certificate-documentation principles used here by analogy.
- NIST Technical Note 2156, Metrological Traceability — traceability as a property of a specific measurement result supported by a documented chain.
- NIST SP 260-136 (2021 ed.) — certificate terminology, uncertainty, traceability, and validity concepts for chemical reference materials.
Limitations: These references provide general analytical, laboratory, measurement, and certificate principles. They do not endorse this checklist or any vendor. ISO 33401 applies to reference-material documentation; its documentation principles are used as a comparison model, not as a claim that a peptide COA is a reference-material certificate.