Quality
How we test
Purity claims are only worth what the document behind them is worth. This page describes what is measured, who measures it, and what we publish as a result.
The process
Specification
Every compound is defined by a written specification before it is made: identity, minimum purity, appearance, and storage. Nothing is released against a looser standard than the one published on its product page.
Synthesis
Material is produced to that specification by the manufacturing partner, in discrete batches. A batch is the unit everything downstream is tracked against.
Independent analysis
A sample from each batch is sent to an analytical laboratory that we do not own and that is not paid on the result. Identity and purity are measured there, not in-house.
Release or rejection
A batch that misses its specification is not released. There is no second grade and no discounted tier for material that failed — it does not enter the catalog.
Publication
The certificate is published against the lot number, including measured content against label claim, and stays online after the lot sells out.
What is tested
A certificate answers four separate questions. They are measured differently, they appear on the document differently, and a certificate that answers only one of them has only answered one.
- What is measured
- Whether the material is the compound named on the label. The molecular mass of the sample is compared with the expected mass of that peptide.
- Method
- Mass spectrometry (MS). The instrument ionises the sample and measures mass-to-charge ratio; a peak at the expected mass is what establishes identity. Some laboratories report it as MALDI-MS or as the MS half of a combined HPLC-MS run.
- On the certificate
- As the method row on the published record, with the laboratory’s own PDF linked in full beneath it. Where a certificate states no method, the row is absent rather than filled in.
Why it matters
A purity figure describes the compound it was measured on. If that compound is not the one on the label, the figure describes something else.
Methods
- HPLC
- High-performance liquid chromatography. Separates the sample into its components and quantifies each, which is what produces a purity figure.
- MS
- Mass spectrometry. Confirms molecular identity by mass, which is what establishes that the compound is the one named on the label.
A purity figure quoted without a method is not a result. Where a certificate names the method, we publish it beside the figure; where it does not, the row is left absent rather than filled in.
The laboratory
Analysis is performed by an independent laboratory. It is not owned by us, not operated by our manufacturing partner, and not compensated according to the result it returns. That separation is the whole reason a third-party figure carries more weight than an in-house one.
The laboratory is named on each certificate where the certificate names it, and on its published record. We do not add a name a certificate does not carry.
Frequency
Testing is per batch, not per year and not per product. Two lots of the same compound are two separate results with two separate certificates, because they are two separate materials. A site that publishes one certificate per product and reuses it is telling you about a batch you did not buy.
Reading a certificate
A certificate can state the lot, the measured purity, the label claim against the measured content, the method, the laboratory, and the test date. We publish each one exactly as issued: a field the certificate does not state is left absent, never filled in. Where label claim and actual content are both stated we show them side by side, because fill processes overshoot slightly by design and showing both is how you demonstrate that the label is not the only number that was checked.
A published certificate
Certificate tested 2026-07-10 · Semax, 10 mg
- Lot
- Not stated on this certificate
- The batch identifier, printed on the vial. It is the only reliable way to tie a physical vial to a specific result. Where a certificate prints none, we headline it by test date and assign nothing.
- Purity
- 99.3%
- The proportion of the sample that is the named compound, by the stated method. Read it with the method row; on its own it is a claim.
- Labeled
- 10 mg
- The label claim — what the vial says it contains.
- Actual
- 11.2 mg (+12.0%)
- The measured content. Fill processes overshoot slightly by design; the difference is shown as a percentage of the label claim.
- Method
- HPLC-UV/MS
- How the figures were produced. HPLC for purity and content, MS for identity — as the laboratory names them.
- Lab
- Krause Analytical
- Which independent laboratory ran the analysis. An unnamed lab is an unverifiable result.
- Tested
- 2026-07-10
- When the analysis was performed. Read it against the lot, not the order date.