Technical note
How to read a certificate of analysis for a pheromone active
Most certificates of analysis in this trade are one page with one number on them. That number is usually an assay, it is usually high, and it is usually not the figure that decides whether the lot will behave like the last one. This is what a certificate has to contain before it can be filed against an incoming-goods procedure.
Identity, before anything else
The certificate should name the compound, quote the CAS number and — where the molecule has geometry — state the isomeric form. Identity is not implied by the product name on the drum; it is asserted on the document that travels with the lot. If the certificate cannot be matched to the container by lot number, it is not a certificate for that container.
Assay, and the basis it is quoted on
An assay figure is meaningless without three pieces of context: the analytical method, the basis (as-is or dried) and the limits. A material quoted at 97% on an as-is basis and one quoted at 97% on a dried basis are not the same purchase. Ask which it is; the answer should be on the page, not in an email.
The method matters for a practical reason. If your laboratory runs a different column and a different temperature programme, two results will not agree to the decimal, and a discrepancy that is really a method difference can hold up a shipment for a week. Agreeing the method at order stage costs one email.
The isomeric ratio, which is the number that matters
For a lure active, the ratio of the named isomer to its partner usually decides field performance more than the assay does. A lot can be 97% pure and carry the wrong geometry in the remaining fraction; a trap does not read the assay.
So the certificate should report the ratio, against a method that resolves the pair. If the chromatogram on the certificate shows a single peak where two isomers should be, the separation was not achieved, and the ratio has not been measured — it has been assumed.
What else belongs on the page
- Lot or batch number, matching the container label and the packing list.
- Date of manufacture and date of release — they are not the same day, and the difference tells you how the lot was held before release.
- Any parameter the customer asked for specifically, reported even when it is inside specification.
- The name of the method, not just “GC”.
What a certificate cannot tell you
It cannot tell you how the material will release from a matrix, how it will age in a finished lure, or how it will perform against a target. Those are properties of the formulation and the field. A certificate is a statement about a container at the moment of release, and treating it as anything more is how people end up blaming the material for a dispenser problem.
How we issue ours
Batch-specific, with identity, assay and isomeric ratio against a named method, and the same lot number as the label. The quality and documentation page describes the full document set; if your incoming inspection needs an extra parameter or an attached chromatogram, say so at enquiry stage and it is included with the lot.
Need the specification behind this?
Send a CAS number and the quantity, and the answer comes back in writing with the isomeric form and packing attached.