How to read a Certificate of Analysis
Don't read the result.
Read the run.
That peak is real. It is the trace from one Aspect certificate, redrawn from the lab's own chromatogram. Follow this sample through the lab and every line on a COA will make sense.
Follow the sampleGHK-Cu 100 mg Lot GHKCu-101926-100 UV 214 nm, ILS Laboratories
Station 1 of 8Received
GHKCu-101926-100
The sample arrives.
Every result on a certificate belongs to one lot. This one reached ILS Laboratories in San Diego on 10/19 and was analyzed on 10/22, and the certificate says who it was tested for: Aspect Peptides.
Look for the lot number on the certificate matching the one on your vial.
Station 2 of 8Separation
99.90%
HPLC pulls the sample apart.
The sample is pushed through a packed column. Different molecules travel at different speeds, so they reach the detector one at a time. Purity is the target's share of what the detector saw. The lab's pass mark here was 95.0%.
Look for a measured figure beside its limit, and the method named.
Station 3 of 8Identity
Confirmed
Is it the right molecule?
Pure is not the same as correct. On this certificate the sample reached the detector at the same time as a reference standard, which is how retention time confirms identity. Many other Aspect certificates use LC-MS/MS, which measures the molecule's mass.
Look for the method named beside the word Confirmed.
Station 4 of 8Net content
107.23 mg
How much is in the vial?
Purity is a share. This is an amount, and neither can stand in for the other. The lab measured 107.23 mg in a vial labeled 100 mg. It is marked Report Only, so it carries no pass or fail: it is simply the number.
Look for a figure in mg you can compare with the label.
Station 5 of 8Fentanyl screen
Not detected
Checking for what should never be there.
An immunoassay screen with a cutoff of 50 ng/mL. Not detected means the sample came in below that cutoff.
Look for the cutoff printed beside the result.
Station 6 of 8Heavy metals
5 of 5
Metals, by ICP-MS.
Reagents and equipment can leave traces of metal behind. ICP-MS measures five of them, each against its own limit. ND means not detected. NMT means not more than.
Look for each metal listed with its own limit and result.
Station 7 of 8Sterility + endotoxin
No growth
Page two: the biological checks.
Sterility is checked by PCR. Endotoxin, which comes from bacterial cell walls, is tested to USP <85>. The limit here is 0.25 EU/mL and this lot is reported at not more than 0.05 EU/mL.
Look for the method and the limit, not only the word Pass.
Station 8 of 8Signed
Signed
A person signs it. You can check it.
The run ends with a lab director's signature, a certificate number and a verify link on the lab's own portal. That link shows you the lab's copy, not the seller's.
Look for a route back to the lab that does not go through the seller.
See this certificate on the lab's portal
The whole record
Now it reads like a story.
This is the complete certificate, both pages. Every pin goes back to its station.
What the small print says
- Purity was calculated by RP-HPLC area normalization at 214 nm.
- Results are capped at 99.9%, so 99.90% is the highest figure this lab reports.
- Results apply only to the sample submitted.
- Product names and lot numbers are supplied by the submitter.
Works on any supplier's COA
The six-point check.
0 of 6 passed
For laboratory research use only. Not for human or veterinary use. Results relate only to the samples tested.