A certificate of analysis is a laboratory's report on one sample. It is not a promise about the whole lot. Read it for which sample, which method, which basis and which date before you read the numbers.
Most buyers read the nicotine line first and the rest of the page never. The numbers are the last thing to trust, not the first. A certificate with the right figures and the wrong sample is worth nothing, and one with a modest figure and a clean paper trail is worth a lot. Here is the order I would read it in.
1. Whose sample, and which lot
Start at the top. You want a sample number, a lot or batch number that matches your shipment documents, the date the sample was drawn and the date it was tested. Check who drew it. A sample the laboratory pulled itself carries different weight from one sent in by the seller.
A certificate for another lot, or for the same lot weeks before packing, proves nothing about the material you are receiving. If the lot number is missing, stop there and ask.
2. Which method produced each number
Every chemistry line should name its method. The families you will meet most are these.
| Line | Method you may see | What it measures |
|---|---|---|
| Nicotine (total alkaloids as nicotine) | CORESTA CRM 85 / ISO 22980 | Continuous-flow analysis |
| Nicotine | CORESTA CRM 62 | Gas chromatography |
| Moisture | CORESTA CRM 76 | Mass lost in a forced-draft oven at 100 °C ± 1 °C for three hours (oven volatiles) |
| Water | ISO 6488 | Karl Fischer titration, specific to water |
| Sand | ISO 2817 | Matter insoluble in hydrochloric acid |
Titration, continuous flow and gas chromatography can all be used for nicotine, and the answers will not always match to the second decimal. A certificate that says "nicotine 3.12%" and nothing else has not told you what was measured. The same goes for moisture. Oven volatiles and Karl Fischer are different measurements, close for many samples but not identical.
3. Basis and moisture, side by side
Next look for the words "as received", "as is" or "dry basis" beside the nicotine. Then look for the moisture result from the same sample. With both, you can convert any figure to the basis your contract uses. Without them you cannot, and a comparison with another laboratory's report is guesswork. The working is in the dry basis article, so it is not repeated here.
4. Decimals, tolerance and honest spread
Natural material varies, and two competent laboratories will not agree to the last digit. Do not read 2.43 against 2.50 as a failure. What you want is a tolerance written into the contract before the result arrives, and a referee laboratory named for the day the results disagree.
The reverse is also a warning sign. If certificate after certificate carries identical figures, ask why. Leaf, scrap and dust do not repeat themselves to the decimal from batch to batch.
5. What the certificate does not cover
A COA reports on the sample it was given. Whether that sample represents the lot depends on how it was drawn, which is a separate question covered in the sampling guide. The certificate also says nothing about lines nobody tested. If foreign matter, sand or particle size matter to you, look for them on the page. If they are not there, they were not measured.
6. Time and transit
A certificate also hides a quiet variable, which is how long the sample sat before anyone tested it. Moisture moves with the air, and a sample left in a loosely closed bag can read differently from the lot on the day it was packed. That flows into every as-received figure on the page. Ask how the sample travelled and how soon it reached the bench. CORESTA Guide No. 13 advises airtight, labelled containers for exactly this reason.
A quick read in five questions
- Does the sample and lot number match my shipment?
- Does each result name a method?
- Is the basis stated, and is moisture reported from the same sample?
- Is the date close enough to packing to mean something, and was the sample sealed?
- Are the lines I care about on the page at all?
When your result differs
Do not argue from the certificate. Test the retained sample, keep the method and basis the same as the supplier's, and compare like with like. If a gap remains, send a sealed split to the agreed third-party laboratory. That route only works if the sample was sealed and labelled at the start, so check that before the shipment, not after.
At Indileaf, every dust batch has its own certificate of analysis, a sealed retained sample is kept for each lot, and a disputed result can go to an agreed third-party laboratory. Ask us the same five questions you would ask anyone, and test a sample first. Request a sample and read the paperwork against the material.
To see which lines are tracked for each product, the products page lists nicotine, moisture and packing side by side.
Frequently asked questions
What is a certificate of analysis in tobacco?
A report from a laboratory on a specific sample, giving the results of the tests run on it. It should identify the sample, the lot, the dates, the methods and the basis of reporting.
Does a COA prove a whole lot meets the specification?
No. It describes the sample tested. How well it describes the lot depends on how the sample was drawn, sealed and handled before analysis.
What should I do if my laboratory result differs from the certificate?
Align the basis and method first, then test the retained sample. If a gap remains, refer a sealed split to the referee laboratory your contract names.
