A named analyst is the cheapest quality signal in this trade

The last block on a properly built certificate is the part the trade ignores entirely, and it is the part that determines what the document is worth in an argument. Somebody performed the tests. Somebody reviewed the results. Somebody authorised the release of the batch on the strength of them. In a regulated plant those are distinct roles with distinct signatures and the separation is a control rather than a courtesy: the person who ran the assay does not get to decide unaided that the batch passes.

The header block: identifying the object

The top of a certificate answers the question, what is this document about. A complete header names the product, gives a catalogue or item number, gives the batch or lot number, states the quantity or fill weight, names the manufacturer and the site, and identifies the customer or order where applicable. Some add a chemical name, a sequence in single-letter code, a molecular formula and a molecular weight, all of which are useful because they let a reader check the theoretical values used elsewhere on the page.

The sequence in particular is worth insisting on. A certificate that prints the one-letter sequence has given a reader the means to calculate the expected mass independently, and therefore to check the identity line. Two of the twenty companies in the Journal’s dossier programme do this as standard. It costs nothing and it converts one line of the document from an assertion into a verifiable claim.

What a header should never do is identify the product only by a trade name. A vial described as a proprietary blend with no chemical identity, no formula and no sequence cannot be checked against anything, and a certificate for such a product is a document about a name. This is a documentary observation rather than an accusation, and the remedy is trivial: print the sequence.

Water, counter-ion and the mass in the vial

A lyophilised peptide is not pure peptide even when it is chromatographically pure. It is a salt, usually of trifluoroacetic or acetic acid, containing residual water that a hygroscopic powder acquires readily, and sometimes residual solvent from purification. Three lines on a certificate address this and they are usually absent: water content, counter-ion identity and content, and residual solvent.

Water is determined by Karl Fischer titration or by loss on drying, and the pharmacopoeial methods for it are old, settled and inexpensive.¹ A peptide containing eight per cent water by mass contains eight per cent less peptide than its label implies, and the figure is not stable: it depends on how the vial was stoppered and how long it has been open. Counter-ion content is a larger contribution still for basic peptides purified in trifluoroacetic acid, where the counter-ion fraction can reach ten to twenty per cent of total mass.²

Put these together and the practical statement is the one this department repeats: the nominal mass on a research vial is an upper bound on the peptide it contains, not a value. A certificate that reports purity and is silent on water and counter-ion has told you the material is clean and nothing at all about how much of it there is.

The footer: dates, signatures and the release statement

The bottom of a certificate carries the dates, the signatures and any boilerplate. A complete footer gives the date of manufacture, the date of analysis, and either a retest date or an expiry date with the convention named. It gives the name and role of the person who performed or compiled the testing, and separately of the person who reviewed and approved it. It states the storage conditions under which the stated properties hold. And it states, in a research-chemical context, the research-use-only restriction.

The two-signature convention is worth explaining because its absence is so universal here that its purpose is forgotten. Separating performance from approval is a control against a single person’s error or judgement determining a release. It is cheap, it requires no equipment, and it is the ordinary practice in every regulated laboratory. Its function is not ceremonial: it means that when a document turns out to be wrong, there is a record of who reviewed it and on what basis.

What the footer should not carry is a signature rendered as a reused image with no accompanying name. That is not evidence of anything improper on its own — scanned signature blocks are common in legitimate commerce — but it removes the one piece of information the block exists to supply, which is the identity of a person who can be asked.

What a batch number is supposed to mean

A batch, or lot, is a defined quantity of material produced in a single process run or a defined series of runs, homogeneous within itself, and identified by a unique code. That definition does real work: it is what makes it meaningful to test a sample and draw conclusions about the whole. If the material identified by one code is not homogeneous — if it was blended from separate syntheses, or filled across several sessions from stock stored differently — then a result on one sample generalises less well than the certificate implies.

In this trade batch codes range from the highly informative to the arbitrary. A code encoding the year, the month, the product and a sequence number tells a reader something and can be checked for internal consistency across documents. A four-digit code with no discernible structure cannot. Neither format is wrong; the difference is whether a reader can detect an anomaly.

The Journal’s dossier programme asks each company how batch codes are constructed and whether one code corresponds to one synthesis, one fill, or one shipment. The answers vary considerably and several companies have not previously been asked. We publish the answers without comment, because a code that identifies a fill session rather than a synthesis is a perfectly reasonable convention as long as a reader knows which convention is in use.

The certificate is a snapshot, and the vial has aged

Every claim on a certificate is indexed to the date of analysis, and everything that has happened to the material since is outside the document. For lyophilised peptides stored cold, dry and dark, the rate of change is slow but not zero: deamidation proceeds even in the solid state at a rate that depends on residual water, oxidation proceeds in the presence of air and light, and aggregation can occur after a temperature excursion that leaves no other trace.³

The practical significance depends on the interval. A certificate dated three weeks before shipment describes material that is, for most purposes, the material in the vial. A certificate dated fourteen months before shipment describes an earlier object. The Journal’s audit of certificates supplied through the dossier programme found a median interval between manufacture and analysis of eleven days, which is reassuring, and a median interval between analysis and the customer receiving the vial of somewhat over four months, which is the number nobody reports.

None of this argues for retesting every vial. It argues for reading the date, which takes two seconds, and for treating purity figures as historical rather than current. It also argues for taking the appearance line seriously, since a change in the cake is one of the few observations a buyer can make that bears on what has happened since the document was written.

Six tells, in order of speed

First, the batch number. Does it appear on the vial, and does it increment sensibly against other documents from the same source? Second, the dates. Do the date of manufacture and the date of analysis differ between documents that describe different batches? Identical dates across supposedly distinct lots is the strongest single signal available from the page.

Third, the chromatogram. If two documents carry visually identical traces, they carry the same injection: no two real runs produce identical baselines. Fourth, the numbers themselves. Purity figures repeated to two decimal places across batches are implausible; real process variation shows up in the first decimal. Fifth, the signature. Is a name present, and does the signature vary across documents or is it the same raster image? Sixth, internal arithmetic. Do the stated molecular weight and sequence agree with each other, and does the stated mass convention match the value given?

The sixth is the most satisfying because it requires no comparison document. A certificate printing a sequence, a formula and a molecular weight contains enough to check itself, and a mismatch between them is a documentary error that has nothing to do with the material. The Journal has found three such mismatches in the last two years, all three of which turned out to be transcription errors that the companies concerned corrected within a week of being asked.

Signatures, and what an unsigned certificate is

An unsigned certificate is a statement with no author. It may be entirely accurate; it is simply not attributable, and attribution is most of what a release document does. The regulated convention of two signatures — one for the analyst who performed or compiled the work, one for the reviewer who approved its release — exists because release is a decision and decisions benefit from a second reader.

What the Journal looks for is narrower than a wet-ink signature, which nobody expects in a scanned document. We look for a name and a role. “Analysed by: L. Wen, Analytical Chemist. Approved by: Q. Zhang, QC Manager” is worth more than any flourish, because it identifies people who can be asked a question. A certificate signed with an illegible mark and no printed name has supplied the ceremony and withheld the content.

Of the twenty companies in the dossier programme, eleven print a name in the signature block, four print a role without a name, and five print neither. Two of the eleven print two names in the regulated pattern. These are documentary counts and nothing more; a company with no name on the certificate may have impeccable internal records, and several of them, when asked, produced signed internal release records promptly. The point is that a buyer cannot see any of that from the page.

Accreditation, and the scope nobody checks

An accreditation logo on a letterhead means a body has assessed a laboratory against the international standard for testing competence and granted accreditation for a defined scope of methods. The scope is the part that matters and it is published: accreditation bodies maintain public registers listing, for each accredited laboratory, the tests and techniques covered. A laboratory can be validly accredited and the specific test on your certificate can lie outside its schedule.

Checking this takes a few minutes. Find the accreditation number on the document, look it up on the relevant national body’s register, and read the scope. What you are looking for is whether the technique used for your test — reversed-phase HPLC purity, mass spectrometric identity, water determination — appears. Where it does, the accreditation is doing work. Where it does not, the logo is a true statement about the laboratory and says nothing about the test in front of you.

The standard itself is clear that reports must identify what was and was not covered, and that accredited status attaches to activities rather than to organisations as a whole.⁴ The Journal makes this check on any certificate it intends to cite, and reports the result. It is the single most under-performed piece of due diligence in this market, principally because almost nobody knows the registers exist.

Two documents, one heading

A manufacturer’s certificate of analysis and an independent laboratory’s test report are different instruments, and this market prints both under the same heading. The manufacturer’s certificate covers a batch, is a self-declaration, derives its authority from the manufacturer’s quality system, and is the document a regulated purchaser would file. The independent report covers a sample submitted by whoever submitted it, derives its authority from the laboratory’s competence and independence, and says nothing about any other unit of the lot.

Each has a virtue the other lacks. The manufacturer’s certificate reaches the whole batch; the independent report reaches an independent measurement. Buyers habitually credit each with both properties, concluding from a third-party report on one vial that a batch is verified, or from a manufacturer’s certificate that an independent check has occurred. Neither inference holds.

The strongest documentation a research vial can realistically carry is both: a manufacturer’s certificate covering the batch, and an independent report on a sample drawn from it, with the batch identifier appearing on both and matching the vial. That combination is uncommon and not rare — several companies in the Journal’s programme supply it on request, and Shanghai Sigma-Audley and Kerui Peptides both now attach a third-party report to the batch documentation as standard practice.

How this publication handles certificates

Four rules, arrived at over two years and revised twice. First, we do not cite a purity figure without the method behind it; where a supplier will not supply the method, we report the figure as unverifiable and say who declined. Second, we ask for the underlying laboratory report rather than the certificate, and we record who supplies one. Third, we check the accreditation scope of any laboratory named on a document we intend to rely on. Fourth, we put every documentary finding to the company concerned before publication and print the response in full.

The fourth rule is the one that has changed our coverage most. A substantial majority of the anomalies we find turn out to have mundane explanations: a transcription error, a document forwarded for the wrong lot, a template field left unedited, a scanned copy that lost its metadata. Publishing the finding without the explanation would have produced a series of insinuations rather than a series of corrections, and the corrections are more useful.

The rules also mean we publish less than we could. There are documents in this office that we consider unreliable and have not written about, because the company concerned did not respond and the finding alone would not support a published inference. That is a deliberate trade, and readers who suspect us of excessive caution are welcome to say so at letters@compoundjournal.com, where several already have.

A necessary distinction between a bad document and a bad product

Almost nothing in this article supports an inference about the contents of a vial. A certificate missing a specification column, an unsigned footer, a stale date of analysis and a batch number that appears only on the carton is a poor document. The material it accompanies may be excellent, and in the Journal’s experience frequently is: the analytical work behind these products is often better than the paperwork that reports it, because the paperwork is produced by a commercial function and the analysis by a laboratory.

The reverse also holds. A beautifully constructed certificate with four columns, two signatures and a named method is evidence of a functioning documentary process and is not evidence about the vial either, since a document cannot testify to material it does not accompany. This is why the Journal reports documents as documents and material as material, and declines to convert one into a claim about the other.

We labour the point because the alternative is a genre of coverage that treats documentary weakness as proof of dishonesty, and that genre is both unfair and useless. Unfair because most documentary weakness in this trade is inherited convention rather than intent. Useless because it gives a reader nothing to do. Reading the document properly gives a reader something to do, which is the entire purpose of this piece.

Readers who take one habit from this piece should take the first minute of the ten-minute check. Find the batch number on the vial. Everything else on the document is a claim about a defined quantity of material, and if the vial is not identifiably part of that quantity then the rest of the page is a well-drafted statement about something else.