Reading a Certificate of Analysis (CoA)
A Certificate of Analysis is your proof of what is actually in the vial. Learn to read HPLC purity, mass-spec identity, batch numbers and the fields that separate a genuine CoA from a meaningless one.
A Certificate of Analysis (CoA) is the document that turns a claim of quality into evidence. For research peptides it is the single most important piece of paperwork you can ask for, because it tells you what compound is in the vial, how pure it is, and which batch it came from.
But a CoA is only useful if you can read it. This guide breaks down the fields you should expect, what the analytical methods mean, and the red flags that suggest a certificate is decorative rather than real.
Every batch at Living Water Labs is HPLC-verified with a batch-specific CoA available on request. Research use only.
WHAT YOU NEED
Tools
- The CoA document (PDF or paper)
Supplies
- The product vial with its batch number
STEP-BY-STEP
Match the batch number to your vial
A genuine CoA is batch-specific. The batch or lot number on the certificate should match the number printed on the vial or its packaging. A certificate that does not reference a specific batch is not evidence about your material.
Tip: No batch number = not a real CoA for your vial. This is the first thing to check.
Confirm the compound identity
The certificate should name the exact compound and, ideally, its molecular formula and molecular weight. This confirms the lab tested the substance you think you bought.
Read the HPLC purity figure
High-Performance Liquid Chromatography (HPLC) separates the sample into its components and reports purity as a percentage — commonly a minimum of 98% for quality research peptides. The HPLC chromatogram should show one dominant peak with minimal others.
Check the mass-spec identity confirmation
Mass spectrometry (MS) measures the molecular weight of the compound to confirm its identity. The measured mass should match the theoretical mass for the named peptide. Purity (HPLC) and identity (MS) answer two different questions — a good CoA has both.
Note the test date and issuing lab
Look for the date of analysis and the name of the testing laboratory. A recent date tied to your batch, from a named lab, is what gives the document weight.
Watch for the red flags
Be sceptical of a CoA with no batch number, no chromatogram image, a purity figure with no method stated, a mismatched compound name, or an image that looks copy-pasted between products. A real certificate is specific and internally consistent.
HPLC vs mass spectrometry — why you want both
HPLC answers "how pure?" It separates everything in the sample and quantifies how much of it is the target compound versus impurities. A 98%+ figure means the vast majority of the material is what it should be.
Mass spectrometry answers "is it the right molecule?" It measures molecular weight to confirm the compound's identity. A sample could be highly pure but be the wrong (or a degraded) molecule — MS catches that.
Together they cover both questions. A certificate that only reports one is telling you half the story.
PUT IT INTO PRACTICE
FREQUENTLY ASKED
What is a Certificate of Analysis?
A CoA is a batch-specific document from an analytical laboratory stating a compound's identity and purity, typically using HPLC (purity) and mass spectrometry (identity confirmation), tied to a specific batch or lot number.
What purity should a research peptide be?
Quality research peptides are commonly HPLC-verified to a minimum of 98% purity. The figure should always be accompanied by the method (HPLC) and, ideally, a chromatogram.
How do I know a CoA is genuine?
It should reference the exact batch number on your vial, name the compound and its molecular weight, state the analytical method, show a chromatogram, and carry a test date and issuing lab. A certificate missing the batch number is a red flag.
Can I get a CoA for my order?
Yes — a batch-specific Certificate of Analysis is available on request for every batch. Reach out via the contact page with your order or batch details.