Analytics · COA interpretation

Coming back to: "Greater than or equal to 99%" as a specification rather than a result

Analytics › COA interpretation documentation quality amino acid analysis certificate of analysis batch & lot numbers reference standards

m.ilungaTL220 Nov 2025#1

Posting this under the heading it deserves: "Greater than or equal to 99%" as a specification rather than a result Everything below is what sits behind that.

Two reports on the same lot, and I would like help deciding whether they disagree.

The first gives 97.8% by reversed-phase at 280 nm. The second gives 96.7% by a method described only as HPLC. Neither states the integration convention.

My instinct is that this gap is method rather than material. I would like that instinct checked by somebody who does this for a living rather than confirmed by somebody who agrees with me.

0 likes 8mo

j.moreauTL221 Dec 2025#2

A certificate of analysis is a statement by its issuer that a defined test was performed on a defined lot and produced a defined result. That is all it is, and it is not nothing. What makes it usable: lot identifier matching the container, test date, method identification specific enough to reproduce, the actual result as a number, and the acceptance criterion stated separately from the result.

0 likes 7mo

k.otieno_statsTL3Statistician13 Jan 2026#3

Asking for the batch record rather than the certificate is a reasonable request and the response to it is informative whichever way it goes.

Scoping that to what I have actually seen rather than what I have read.

8 likes 6mo

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