A COA is a record of tests on an identified sample or batch. A product specification states the limits agreed for supply. A technical data sheet describes a grade more broadly. Read these documents together rather than treating a single percentage as the whole quality decision. For the wider procurement packet, see documents to request before buying amino acid powder.
1. Start with identity and traceability
Check the product name and grade (for example, Amino Acids 45 or Amino Acids 80), manufacturer or issuing laboratory, report number, batch or lot number, sample identification, sampling or receipt date, test date and authorization. Match the batch identifier to the label, packing list and purchase order. If the document identifies only a sample and no production batch, ask what lot it represents.
A third-party report and a manufacturer's batch COA can serve different purposes. A third-party result supports the tested sample; it does not automatically certify every later shipment. Ask which organization sampled the material and whether the sample came from the shipment you will receive.
2. Read results against limits and methods
| COA field | What to check | Question to ask if missing |
|---|---|---|
| Specification or acceptance limit | Is the result inside the agreed minimum, maximum or range? | Which version of the specification governs this order? |
| Measured result and unit | Is the number an actual measurement, and is it %, g/kg or another unit? | Can you provide the numeric result rather than “passes”? |
| Method | Which preparation, analytical method and analytes produced the result? | What method and calculation define this line item? |
| Reporting basis | Is the value as received, dry basis or another stated basis? | What moisture correction, if any, was applied? |
When comparing suppliers, align methods, units and reporting bases before comparing percentages. Also distinguish a measured value from a rounded specification threshold. Generic COA guidance from the Australian Therapeutic Goods Administration illustrates why batch identity, tests, results, acceptance criteria and methods belong together; that guidance is for listed medicines, not a fertilizer standard.
3. Interpret the amino acid lines
Total amino acids and free amino acids are different measurements. A total assay commonly includes an analytical hydrolysis step that releases amino acids from proteins and peptides; a free assay measures unbound amino acids without that step. The Texas A&M University Protein Chemistry Lab explains the analytical distinction. Read our free vs total amino acids guide for a full comparison.
An “AA80” label generally refers to a total amino acid grade, not a promise of 80% free amino acids. If a COA reports an individual amino acid profile, check which analytes were included and whether the reported sum matches the stated total method. Do not infer an exact peptide fraction by subtracting free from total unless definitions, analyte coverage and reporting bases are compatible.
For nitrogen, identify whether the line says total nitrogen or organic nitrogen; they are not interchangeable. The difference and common calculation pitfalls are covered in our nitrogen COA guide.
4. Check the properties relevant to your use
Depending on the grade and your formulation, request moisture, pH with its solution concentration, chloride or sodium where relevant, solubility or insoluble matter with test conditions, and any market-specific contaminant tests required by your agreed specification. A “100% soluble” statement needs the test concentration, water quality, temperature, mixing time and criterion for visible residue to be comparable. See the amino acid powder solubility guide and run a bench test at your intended use concentration.
A COA does not establish that a powder will be compatible with every tank mix or deliver a particular crop response. Use it to screen and release material against documented requirements; use formulation and application testing for performance questions.
5. Use a representative report correctly
Everwell publishes a representative Eurofins AA80 report, certificate AR-26-Y3-008791-02. It reports 75.37% free amino acids for the tested sample under GB/T 18246-2019 and lists individual amino acids. It is useful evidence for that sample. It is not a claim that every AA80 shipment has exactly 75.37% free amino acids. For an order, request the current batch COA and the agreed product specification.
Buyer checklist before release
- Match the grade, batch number and document identity to the shipment.
- Confirm the issuer, sampling details, dates and authorized report status.
- Compare every required numeric result with your agreed limits.
- Check the method, unit, analyte scope and as-received or dry basis.
- Read total and free amino acids separately; review the profile and nitrogen type.
- Check moisture, pH, salts and solubility under relevant test conditions.
- Resolve missing results or discrepancies with the supplier before acceptance; keep a retained sample for your own verification plan.
Frequently asked questions
Is a representative lab report the same as a batch COA?
No. A representative report describes the sample tested. For shipment acceptance, request a COA linked to the actual production batch and compare it with the agreed specification.
Does AA80 mean 80% free amino acids?
No. AA80 usually names a total amino acid grade. Free amino acids are a separate measurement. Check both definitions, methods and reporting bases.
Can a COA alone prove fertilizer performance?
No. A COA reports specified tests on a sample or batch. It does not replace dissolution, formulation compatibility and application testing under the intended conditions.
What if a COA says only “passes” for a numeric test?
Ask for the measured result, unit, acceptance limit and test method. A pass statement alone makes supplier and batch comparisons difficult.
Sources and further reading
- Texas A&M University Protein Chemistry Lab — Amino Acid Analysis (free and total method distinction).
- Australian Therapeutic Goods Administration — Understanding quality requirements for listed medicines (general COA document fields; different industry).
- Everwell AA80 representative Eurofins report (sample-specific analytical example).
Need a batch-specific COA?
Tell us your grade, required specification and destination market. Request the current batch documents and a sample for your own checks.