is 96.8% area% actually fine or am i being sold a rounding error
CPC semaglutide 10mg. COA says 96.8%, method line says "HPLC", batch and date both present. Nothing cropped, whole page. Everyone in here talks about 98 and 99 like they are the floor, and 96.8 feels like it should bother me, but I genuinely cannot tell whether 1.5 points is a real difference or a decimal I should…
The honest answer is "it depends what the 3.2% is", and the COA you are holding does not tell you.
96.8% area means the main peak is 96.8% of what the detector saw. The other 3.2% is something, and the question that matters is whether it is a related substance you would expect — a des-amido form, an oxidation product, a truncation — or something that has no business being there.
A proper document lists related substances individually. Yours says "HPLC" and gives you one number, which is a technique and a total rather than a method and a breakdown. That is the actual problem here, not the 96.8.
oh. so the number is not the issue, the missing breakdown is the issue.
correct. 96.8 with a listed impurity profile is a document. 96.8 with nothing is a claim.
and 96.8 would pass plenty of legitimate specifications. compendial limits for related substances are not 0.5% across the board — people in here have anchored on a number that came from marketing copy rather than from any standard.
this thread has already been worth more than the last twenty i read
Which is why we make people post the whole page. Half the value of this community is in the fields people crop out.
if there is a chromatogram attached, post that too. the shape of the 3.2% tells you more than the size of it.