Sampling Dates, Analysis Dates and Report Dates
Separate the events
Several dates can appear on a single certificate because several events occurred. Sampling is when material was selected. Receipt is when the laboratory accepted it. Analysis may cover one day or several runs. Issue is when the report was authorised or released. Record each event under its own heading.
For UK records that may be shared internationally, write dates unambiguously, for example 12 September 2026. Preserve the original date format too if a source document could be read in more than one way. Do not resolve an ambiguous date by assumption.
Ask what happened between dates
A timeline becomes useful when it includes the material’s history. Was the submitted sample retained before dispatch? Was analysis delayed? Was a report reissued after an administrative correction? None of these events proves a problem, but each can affect the question the document answers.
The sampling framework in Eurachem’s uncertainty-from-sampling guide includes preparation as well as measurement. As a practical extension, record relevant transport or storage information with the dates rather than treating the instrument run as the material’s entire history.
Do not turn a report into an expiry claim
A report issued last week might describe an analysis performed months earlier. A date on that report is not automatically a retest date, shelf-life statement or guarantee of present condition. Those conclusions require the appropriate evidence for the material and circumstances.
The dating and stability sections in ICH Q7 treat these as distinct topics. This pharmaceutical reference helps explain the distinction; it does not establish a shelf life for an unspecified research peptide. Request the basis of any supplier dating statement separately.
Write the timeline you can support
Create one line for sampling, receipt, analysis and issue, adding “not stated” where necessary. Link every entry to its source. If an amended document arrives, keep the earlier version and note whether the amendment changed a date, a result or only presentation.
Compare the document in the COA library with your own receipt record. If a long interval could matter for the planned assay, ask the supplier or laboratory a focused question about that interval.
The final review should say which sample the timing describes and which later events remain outside the report. An honest incomplete timeline is more useful than a confident one constructed from dates that mean different things.
Related research reading
- Laboratory Accreditation: Read the Scope, Not Just the Badge
- What Raw Analytical Data Adds to a Short Certificate
Explore the research blog and original batch-document library for further context.