Purity claims are easy to make and hard to check. Here is what the testing involves and what a certificate should show you.
Purity claims are easy to make and hard to verify, which is exactly why they are worth
understanding. Here is what the testing actually involves and what to look for.
The two tests that matter
HPLC: how much of it is the compound
High-performance liquid chromatography pushes the sample through a column that separates its
components. The output shows each component as a peak, and the relative area of those peaks gives
the purity percentage. A 99%+ result means at least 99% of the material is a single component.
Mass spectrometry: whether that compound is the right one
HPLC tells you the sample is 99% one thing. It does not tell you what that thing is.
Mass spectrometry measures molecular weight, confirming the identity of the compound.
Both together, or neither means much. A purity figure without an identity
confirmation tells you a vial contains 99% of something. That is not the same as 99% of what
you ordered.
What to look for on a certificate
A batch or lot number that matches the vial you received.
A test date, an old certificate on new stock is a red flag.
The testing laboratory named, not just “third-party tested”.
The chromatogram itself, not only a summary figure. The trace shows the
peaks; a number alone can be typed by anyone.
Both HPLC and MS results, for the reason above.
How we handle it
Every batch we stock is independently tested before it reaches our shelves, and the certificates
are published on our Purity Results page. If you need the certificate for a specific batch, ask the team and we will send it through.
We would rather you checked. A supplier who is reluctant to produce a batch-matched certificate
is telling you something.
Common questions
What is a certificate of analysis?
A lab report for a specific batch, showing what was tested, by which method, and what the result was. It is batch-specific, a certificate for one batch says nothing about another.
What does HPLC test?
High-performance liquid chromatography separates the components of a sample and measures their relative proportions, which is how purity percentage is determined.
What does mass spectrometry add?
HPLC shows how much of the sample is one component; mass spectrometry confirms that component is the molecule it should be, by measuring its molecular weight.
What does 99%+ purity actually mean?
That at least 99% of the material in the vial is the stated compound, as measured by HPLC. The remainder is typically residual solvents and process-related impurities.
Can I see the COA for my batch?
Yes. The certificates are published on our Purity Results page. For a specific batch, give the team your order reference and we will send that one through.
Why does batch-specific matter?
Because a supplier can publish one good certificate and ship different material. A certificate is only meaningful if it matches the batch in your hand.
Still stuck?
Message the team on Telegram and we will sort it out, usually within minutes.
For research use only. Everything on this page describes laboratory handling of research materials: volumes, concentrations, storage and shipping. It is not medical advice, not a dosing recommendation, and not a claim of any effect in humans. Evra Peptides products are not for human or veterinary consumption, nor for diagnostic or therapeutic use. You must be 18 or over to order.