10 Questions That Expose a Weak Peptide COA: The Checklist Built From ICH and FDA Standards (2026)

A weak certificate of analysis (COA) is one that cannot answer ten plain questions: which lab, sample, lot and dates; whether identity, purity and content methods are named; whether endotoxin and impurity lines are reported or marked not tested; and whether an expiry date is shown. peptideecommerce.com's own tool data lists these 10 questions and 15 glossary entries. (OPS-089, OPS-098, OPS-020, OPS-034)

Updated October 28, 2026.

All checklist and glossary material in this article is peptideecommerce.com's own tool data, read from its COA glossary file. It is not a finding about any laboratory or seller, and this article does not say that any lab or seller passes or fails.

What are the 10 questions on the COA checklist?

The checklist has 10 questions, and this article matches each by topic to a glossary entry that names a published standard. (OPS-089, OPS-090, OPS-091, OPS-092, OPS-093, OPS-094, OPS-095, OPS-096, OPS-097, OPS-098) peptideecommerce.com's COA checklist tool asks the questions in the table below. (OPS-089, OPS-098) The tool data records the questions and the glossary entries as separate lists, so the pairing shown in the table is this article's topic match and not a pairing the tool data records. (OPS-089, OPS-098, OPS-020, OPS-034) Each standard named in the table is the source body that the matched glossary entry itself names. (OPS-030, OPS-020, OPS-034, OPS-028, OPS-029, OPS-031, OPS-032, OPS-033) Compare each question in the table with the certificate in front of you. (OPS-089, OPS-098)

Which source body each checklist question's closest glossary entry names

Where does the checklist come from?

The glossary behind the checklist has 15 entries, and each entry names one source body. (OPS-020, OPS-021, OPS-022, OPS-023, OPS-024, OPS-025, OPS-026, OPS-027, OPS-028, OPS-029, OPS-030, OPS-031, OPS-032, OPS-033, OPS-034) Eight entries name ICH Q6A. (OPS-020, OPS-021, OPS-022, OPS-023, OPS-024, OPS-025, OPS-026, OPS-027) One entry names ICH Q3D(R2). (OPS-028) One entry names ICH Q2(R2). (OPS-029) Four entries name sections of 21 CFR Part 211, namely 211.194(a)(1), 211.194(a)(2), 211.165(a) and 211.137(b). (OPS-030, OPS-031, OPS-032, OPS-033) One entry names FDA guidance on pyrogen and endotoxin testing. (OPS-034) In plainer words, the glossary entries cite ICH, 21 CFR Part 211 and FDA guidance as their source bodies. (OPS-020, OPS-034)

Do the ICH documents apply to research peptides?

The tool data says its ICH references are not a statement that any given research peptide must follow them. (OPS-073) The glossary note states: "ICH Q6A, Q2(R2) and Q3D are written for pharmaceutical drug substances and products; they are cited as published standards for what each COA field means, not as a statement that any given research peptide must follow them." (OPS-073) In plainer words, the ICH documents are cited for what a COA field means, not as a statement that a given research peptide must follow them. (OPS-073) When you read the ICH wording quoted in this article, treat it as a reference point for a field's meaning. (OPS-073)

What is in the glossary, and which standard does each entry cite?

The glossary pairs each COA field with a short check and a named source body, and the table below lists the entries. (OPS-020, OPS-034) The check column repeats the check text as the tool data records it. (OPS-020, OPS-034) That check text is peptideecommerce.com's own tool data and not the text of the standards. (OPS-020, OPS-034) Read the check column, then open the standard named in the source body column. (OPS-020, OPS-034)

Does the report name the lab, the sample, the lot number and the dates?

Two checklist questions ask whether a report names its lab, sample, lot and dates and whether the lot number matches the vial. (OPS-089, OPS-090) The tool data's glossary entry "Sample description, source and lot number" names FDA, 21 CFR 211.194(a)(1) as its source, and its check reads: "That the lot number on the report matches the vial label, with source and dates stated." (OPS-030) In plainer words, the checklist question and the glossary check both ask that the lot on the report be the lot on the vial. (OPS-090, OPS-030) Compare the lot number on your report with the vial label, and check that source and dates are stated.

The 21 CFR 211.194 wording recorded for the sample entry calls for "A description of the sample received for testing with identification of source (that is, location from where sample was obtained), quantity, lot number or other distinctive code, date sample was taken, and date sample was received for testing." (source: eCFR, 21 CFR 211.194). (OPS-084) In plainer words, the quoted text lists source, quantity, lot number or other distinctive code, the date the sample was taken and the date it was received for testing. (OPS-084) Look for those items on the report you are reading. (OPS-084)

How should a COA show identity?

One checklist question asks whether identity is shown by a method that can tell the compound from close relatives. (OPS-091) The Identity glossary entry, which names ICH Q6A, tells the reader to check which method is named (for example mass spectrometry or a reference comparison) and whether identity rests on more than one retention time. (OPS-020) The "Identity by retention time alone" entry, which also names ICH Q6A, checks whether identity relies only on one HPLC retention time, which ICH Q6A does not regard as specific. (OPS-021) In plainer words, the tool data asks which identity method a certificate names and whether it goes beyond one retention time. (OPS-020, OPS-021) Check which method your certificate names for identity. (OPS-091)

The Identity entry, matched by topic to the identity question (OPS-091), records ICH Q6A wording that "identification testing should optimally be able to discriminate between compounds of closely related structure which are likely to be present" (source: ICH Q6A). (OPS-074) In plainer words, the sentence says identification testing should ideally be able to discriminate between compounds of closely related structure that are likely to be present. (OPS-074) Ask whether the identity method on a certificate can separate close relatives. (OPS-074)

The tool data flags identity by a single retention time as a point to check. (OPS-021) The "Identity by retention time alone" entry records: "Identification solely by a single chromatographic retention time, for example, is not regarded as being specific." (source: ICH Q6A). (OPS-075) In plainer words, ICH Q6A does not regard identification solely by one chromatographic retention time as specific. (OPS-075) The tool data's check asks whether identity relies only on one HPLC retention time. (OPS-021) Check whether the identity line on a certificate rests on more than a retention time. (OPS-075, OPS-021)

Is the purity method named, and is content reported separately?

Two checklist questions ask whether the purity method is named with its basis and whether a content value is reported separately from purity. (OPS-092, OPS-093) The tool data's check for purity is that the report states the method, the detection setting and what the percentage is calculated from. (OPS-023) Its check for assay is that a content value is reported with the method used, separate from the purity percentage. (OPS-022) In plainer words, the checklist wants the purity figure explained by its method and basis, and the content figure reported on its own. (OPS-092, OPS-093) Look on a certificate for a purity method with its basis and a separate content value. (OPS-092, OPS-093)

The "Assay (content)" entry records this ICH Q6A wording: "Assay: A specific, stability-indicating procedure should be included to determine the content of the new drug substance." (source: ICH Q6A). (OPS-076) In plainer words, the sentence says a specific, stability-indicating procedure should be included to determine content. (OPS-076) The "Purity and impurities (HPLC)" entry records: "In many cases it is possible to employ the same procedure (e.g., HPLC) for both assay of the new drug substance and quantitation of impurities." (OPS-077) In plainer words, the sentence says one procedure, HPLC for example, can serve for both assay and impurity quantitation. (OPS-077) Look on a certificate for a named procedure behind its content and purity lines. (OPS-076, OPS-077)

Is an endotoxin result reported with its method, or marked not tested?

One checklist question asks whether an endotoxin result is reported with its method or marked not tested. (OPS-094) The Endotoxin glossary entry's check is whether a result is reported with the method named, or the line is blank. (OPS-024) The ICH Q6A wording recorded for that entry reads: "Endotoxins/Pyrogens: A test procedure and acceptance criterion for endotoxins, using a procedure such as the limulus amoebocyte lysate test, should be included in the specification." (source: ICH Q6A). (OPS-078) In plainer words, the sentence says the specification should include a test procedure and an acceptance criterion for endotoxins. (OPS-078) Check your certificate for an endotoxin method and for a stated result or a not tested mark. (OPS-094, OPS-024)

The FDA guidance recorded in the pyrogen and endotoxin testing entry says it will "recommend that appropriate components and finished products be tested for the presence of pyrogens and endotoxins" (source: FDA, Pyrogen and Endotoxins Testing: Questions and Answers). (OPS-088) In plainer words, FDA recommends that appropriate components and finished products be tested for pyrogens and endotoxins. (OPS-088) The tool data check for that entry is whether a stated endotoxin result is paired with a named method. (OPS-034) If a certificate states an endotoxin result, check that a named method is stated with it. (OPS-034)

Are microbial, water, residual solvent and elemental impurity lines present?

One checklist question asks whether microbial, water, residual solvent and elemental impurity lines are present or marked not tested. (OPS-095) Three of those lines match glossary entries that name ICH Q6A, namely Microbial limits, Water content, and Residual solvents and impurities. (OPS-025, OPS-026, OPS-027) The elemental impurities line matches the entry that names ICH Q3D(R2). (OPS-028) The table below gives each entry's recorded evidence quote and the standard it comes from. (OPS-079, OPS-080, OPS-081, OPS-082) Compare the wording in the table with the lines on your certificate. (OPS-079, OPS-080, OPS-081, OPS-082)

Is each result listed with its method and its acceptance limit?

One checklist question asks whether each result is listed with its method and its acceptance limit. (OPS-096) This article matches three glossary entries to it by topic. (OPS-031, OPS-029, OPS-032) "Method statement" cites 21 CFR 211.194(a)(2), and its check is that each result lists the method used. (OPS-031) "Method specificity" cites ICH Q2(R2), and its check is that the report names the method and that a validated method is cited. (OPS-029) "Identity and strength before release" cites 21 CFR 211.165(a), and its check is that a specification is stated and each result is compared to it. (OPS-032) Check whether each result on a certificate lists its method and its limit. (OPS-096)

The method statement entry records 21 CFR 211.194 wording calling for: "A statement of each method used in the testing of the sample." (source: eCFR, 21 CFR 211.194). (OPS-085) In plainer words, the sentence calls for a statement of each method used in testing the sample. (OPS-085) The method specificity entry records: "Specificity is typically used to describe the ultimate state, measuring unequivocally a desired analyte." (source: ICH Q2(R2)). (OPS-083) In plainer words, the sentence describes specificity as measuring a desired analyte unequivocally. (OPS-083) Look for a named method with each result on a certificate. (OPS-085, OPS-083)

21 CFR 211.165, as recorded for the identity and strength entry, says: "there shall be appropriate laboratory determination of satisfactory conformance to final specifications for the drug product, including the identity and strength of each active ingredient, prior to release." (source: eCFR, 21 CFR 211.165). (OPS-086) In plainer words, the sentence calls for laboratory determination of conformance to final specifications, including identity and strength, before release. (OPS-086) The tool data's check for the entry is that a specification is stated and each result is compared to it. (OPS-032) Look for a stated specification and check that each result is compared to it. (OPS-032)

Is an expiry or retest date shown with storage conditions?

One checklist question asks whether an expiry or retest date is shown with storage conditions. (OPS-097) This article matches it by topic to one glossary entry. (OPS-033) The "Expiration date" entry cites 21 CFR 211.137(b), and its check is whether an expiry or retest date is shown with storage conditions. (OPS-033) The recorded 21 CFR 211.137 sentence reads: "Expiration dates shall be related to any storage conditions stated on the labeling, as determined by stability studies" (source: eCFR, 21 CFR 211.137). (OPS-087) In plainer words, the sentence says expiration dates shall be related to any storage conditions stated on the labeling, as determined by stability studies. (OPS-087) Check that any expiry or retest date on a certificate comes with storage conditions. (OPS-097, OPS-033)

Can the report be checked with the lab that issued it?

One checklist question asks whether the report can be checked with the lab that issued it. (OPS-098) The sources captured for this guide do not say which glossary entry or standard this question rests on. Contact the lab named on a certificate and ask it to confirm the report. (OPS-098)

What does this checklist not do?

The checklist is a list of questions to put to a certificate. (OPS-089, OPS-098) This article reports no lab result and says no lab passes or fails. The sources captured for this guide do not rate or rank any lab. Use the questions to compare each certificate you receive against the same list. (OPS-089, OPS-098)

How current is the data?

The tool data lists 2026-10-07 as the retrieved date for the COA glossary. (OPS-072) The glossary entries for the cited standards also record 2026-10-07 as the retrieved date. (OPS-074, OPS-075, OPS-076, OPS-077, OPS-078, OPS-079, OPS-080, OPS-081, OPS-082, OPS-083, OPS-084, OPS-085, OPS-086, OPS-087, OPS-088) Check the retrieved date against the date of any standard you rely on. (OPS-072)

FAQ

How many questions are on the checklist?

peptideecommerce.com's COA checklist tool data lists 10 questions. (OPS-089, OPS-090, OPS-091, OPS-092, OPS-093, OPS-094, OPS-095, OPS-096, OPS-097, OPS-098)

Which standards does the glossary cite?

It cites ICH Q6A, ICH Q2(R2), ICH Q3D(R2), 21 CFR 211.194(a)(1), 21 CFR 211.194(a)(2), 21 CFR 211.165(a), 21 CFR 211.137(b) and FDA guidance on pyrogen and endotoxin testing. (OPS-020, OPS-028, OPS-029, OPS-030, OPS-031, OPS-032, OPS-033, OPS-034)

Must a research peptide follow ICH Q6A?

The tool data note says the ICH documents are cited as published standards for what each COA field means, not as a statement that any given research peptide must follow them. (OPS-073)

Does the ICH text treat a single retention time as specific identification?

The recorded ICH Q6A quote says identification solely by a single chromatographic retention time is not regarded as being specific. (OPS-075)

Should endotoxin be reported with a method?

The tool data check says to see whether an endotoxin result is reported with the method named, or the line is blank. (OPS-024)

Should the lot number on the report match the vial?

Checklist question 2 asks exactly that, and the glossary entry for sample and lot number repeats the check. (OPS-090, OPS-030)

Does the checklist say which labs are reliable?

The sources captured for this guide do not rate or rank any lab. The checklist is a list of questions to put to a certificate. (OPS-089, OPS-098)

Sources

This article states what peptideecommerce.com's tool data records. It is not legal advice. Talk to a licensed attorney for your situation.