Annotated certificate of analysis explorer

Certificate of analysis (specimen)

Illustrative specimen. No lab issued this certificate. Every value on it is made up for teaching.

Lab: Example Analytical Lab (fictional). Material: Example peptide. Client: Example Client Co (fictional). Lot: LOT-EX-0001.

A certificate of analysis reports tests performed on a particular sample. It does not report on every unit in a lot, and it is not a statement about legal status. A certificate of analysis records tests performed on a particular sample (WHO Model Certificate of Analysis). (source guide)

Every part of the specimen, annotated

1. Lab identity and report record

   On the specimen: Example Analytical Lab (fictional). Site: Example City. Report number EAL-SPECIMEN-0001, version 1. Accreditation line: none, because no lab exists.

   What it shows

   • The lab name, site, report number and version tell you which file you hold. Write down the legal lab name and the site shown on the file. Keep the report number and version. (source guide)

   What it cannot show

   • A report number names a file. It does not show that the lab issued it. A report number identifies a file; confirm separately that the lab issued it. (source guide)
   • A clean layout is only a layout. A clean layout shows formatting; confirm separately that the report is real. (source guide)

   What to check on any report you receive

   • Ask the lab to confirm the report number, version, sample code, dates and approval. Ask the lab to confirm the report number, version, sample code, dates, and approval. (source guide)
   • Confirm the lab's scope and the signer through their own records. Confirm the issuer, signer, and lab scope through their own records (source guide)

2. Material name and form

   On the specimen: Example peptide. Form as written on the specimen: acetate salt (illustrative).

   What it shows

   • The name field is what the report calls the sample. The name field states what the report calls the sample. (source guide)

   What it cannot show

   • A short name may not show which form a method or mass value refers to. A short peptide name may not show which form the method or mass value represents. (source guide)

   What to check on any report you receive

   • Compare the name on the report with the item record. Compare the report name with the item record. (source guide)
   • Ask which material the lab received and which form the stated value uses. Ask which material the lab received and which form the stated value uses. (source guide)

3. Client, sample and lot

   On the specimen: Client: Example Client Co (fictional). Sample code: S-EX-0001. Lot number: LOT-EX-0001.

   What it shows

   • The lot code on a report is meant to be checked against the item, stock and sample records. The lot code on a report should be checked against the item, stock, and sample records. (source guide)

   What it cannot show

   • A report covers the sample the lab received, which can differ from a claim about the whole lot. A certificate can report on the sample the lab received (World Health Organization), which can differ from a claim about the full lot. (source guide)
   • A matching code is one useful record check, not the whole chain. A matching code is useful record evidence. (source guide)

   What to check on any report you receive

   • Ask who took the sample, where it came from and what record links it to the lot. Ask who took the sample, where it came from, how it was split, and what record links it to the lot. (source guide)
   • If one link is missing, treat attribution to the lot as an open question. If one link is absent, record attribution to the lot as an open question. (source guide)

4. Dates: received, tested, issued

   On the specimen: Received 2026-01-05. Tested 2026-01-07. Issued 2026-01-09. All dates are illustrative.

   What it shows

   • Each date marks its own event. Read each date for its own event. (source guide)

   What it cannot show

   • A test date is not a lot make date, and an issue date is not a sampling date. a test date marks only when the test occurred, separate from when the full lot was made, and an issue date marks only when the file issued, separate from when the sample was drawn (source guide)

   What to check on any report you receive

   • Ask the issuer to confirm the report number, version, sample code, test date and approval date. Ask the issuer to confirm the report number, version, sample code, test date, and approval date. (source guide)
   • Read the dates in order and ask about any gap. Read the dates in order. Ask about a gap, change, or report that was replaced. (source guide)

5. Test methods: HPLC and mass spectrometry

   On the specimen: Purity by HPLC with UV detection, method EX-HPLC-01 version 1. Identity by mass spectrometry, method EX-MS-01 version 1. Both are illustrative.

   What it shows

   • The test name tells you the question the lab meant to ask. The test name tells you the question the lab meant to ask. (source guide)
   • The method tells you how the lab sought the answer. The method tells you how it sought the answer. (source guide)

   What it cannot show

   • A broad test name is not enough when the method and version are missing. A name such as identity, chromatography, water, or content is still too broad when the method, version, and test basis are absent. (source guide)

   What to check on any report you receive

   • Ask which method and which version were used. Ask which method and version were used. (source guide)

6. Purity result (HPLC)

   On the specimen: Purity: 98.6 % by peak area. Stated limit: not less than 95.0 %. Result line: meets the stated limit. All values are illustrative.

   What it shows

   • A chromatography result may show detector response and split peaks under that method. A chromatography result may show detector response and split peaks under that method. (source guide)

   What it cannot show

   • Area purity and peptide mass purity are different measurements. Chromatographic area purity and peptide mass purity are different measurements (source guide)
   • An area percent has to be read within its method, detector and sample. Read a chromatography area percent within its method, detector, response, integration, and sample. (source guide)

   What to check on any report you receive

   • Read the unit before the number. Read the unit before the number. (source guide)
   • Read the limit beside the method and the unit. Read the criterion beside the method and unit. (source guide)

7. Identity result (mass spectrometry)

   On the specimen: Expected neutral mass 1000.00 Da. Observed neutral mass 1000.12 Da, calculated from the [M+2H]2+ ion at m/z 501.07. Difference +0.12 Da. Tolerance stated on the specimen: plus or minus 0.50 Da. All values are illustrative.

   What it shows

   • A mass match may support a narrow mass based identity question under the stated method. It may support a narrow mass based identity question under the stated method. (source guide)

   What it cannot show

   • A mass match is a mass finding. Full identity and purity need their own tests. Read a mass match as a mass finding, and confirm full identity and purity through their own tests. (source guide)
   • Different structures can share the same or a very close mass. Different structures can share the same or a very close mass. (source guide)

   What to check on any report you receive

   • Ask whether the report gives a raw mass to charge value, a calculated neutral mass or a processed result. Ask whether the report gives raw mass to charge (m/z), a calculated neutral mass, or a processed mass result. (source guide)
   • Ask the lab which mass tolerance it set for the method and how it validated the method. Ask the lab which peptide mass tolerance it set for this method and how it validated that method (source guide)
   • Make a pass or fail call only against a valid criterion. Make a pass or fail call only against a valid criterion. (source guide)

8. Net content and peptide content

   On the specimen: Net content: 10.0 mg per vial as filled. Peptide content: 82.0 % by weight, method EX-AAA-01. All values are illustrative.

   What it shows

   • A content or assay result may show an amount under the stated test and basis. A content or assay result may show amount under the stated test and basis. (source guide)

   What it cannot show

   • A result supports only the test question, sample and method shown. A result supports only the test question, sample, and method shown. (source guide)

   What to check on any report you receive

   • Keep any less than sign or range exactly as shown. Keep less than signs, ranges, and other marks exactly as shown. (source guide)
   • Read every note, because a note can limit what the result supports. Such notes can limit what the result supports. (source guide)

9. Signature and authorisation

   On the specimen: Approved by: Example Reviewer, Quality Reviewer (fictional). Approval date 2026-01-09. No real person signed this specimen.

   What it shows

   • Approval shows the report was signed or accepted within the issuer's own system. Approval shows the report was signed or accepted within the issuer system (World Health Organization). (source guide)

   What it cannot show

   • A plausible appearance does not establish authenticity. A plausible appearance does not establish authenticity (source guide)

   What to check on any report you receive

   • Confirm who made the mark and whether the signer had the stated role. Confirm who made the mark and whether the signer had the stated role through the lab. (source guide)

10. Verification code or lookup

    On the specimen: Verification: none. This specimen has no real code, because no lab issued it. A real report may carry a barcode or tracking number.

    What it shows

    • Some reports carry barcodes or tracking numbers that should match other documentation. Legitimate COAs typically include authorized signatures, dates, and sometimes barcodes or tracking numbers that match other documentation. (source guide)

    What it cannot show

    • Appearance alone cannot show who created a document. document appearance alone cannot establish who created it (source guide)
    • A code on the page does not show the issuer confirmed the report. A report number identifies a file; confirm separately that the lab issued it. (source guide)

    What to check on any report you receive

    • Find a contact path for the lab on its own site or another known record, not only on the certificate. Find a contact path on the lab site or another known record, not only on the certificate. (source guide)

Check any report you receive

1. Match the file to the lot and sample records first. First match the file to the lot and sample records. (source guide)
2. Note the lab, report number, version and approver. Name the lab, site, report number, version, page count, sample code, and lot code. (source guide)
3. Write down each date with its label. List each date with its label. (source guide)
4. Record the method, limit, unit and result for each test. For each test, record the method, the stated limit, the unit, and the result. (source guide)
5. Read the unit before the number. Read the unit before the number. (source guide)
6. Read every comment on the report. Then read every note. (source guide)
7. Contact the lab through a route you found yourself and ask it to confirm the report. ask the lab to confirm the report through a contact path you found on its own site (source guide)
8. Where a field is missing, name the gap and ask for the record. Name the missing field and the claim it leaves open. (source guide)

Related guides

• How to read a peptide certificate of analysis
• How to spot a forged COA