A report I filed that turned out to be wrong, and the correction posts 61–90
This is a continuation of a long topic, addressed by post number rather than by page. Start at post 1.
Report the certificate figure alongside the independent one. The comparison is the point and it is the part most often omitted.
Acknowledging rather than arguing. The reasoning holds as far as I can follow it.
Taking post #61 at face value and following it one step further.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
I have separated what I observed from what I concluded, which does not always happen.
Where you have no independent result, a documentation report is still worth filing: what the certificate contained, what it omitted, and how fast a request was answered.
That is the version I would defend. It is not the version I started with.
Comparing your result to somebody else's on a different lot is not a comparison of suppliers. Lot is the unit and it should be in every report.
I have deliberately not rounded that, because the rounding is where the argument starts.
Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion, and excipient. Purity and content are different. Both matter for different reasons.
Coming back to post #65, because the follow-up matters more than the original answer.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
The conclusion is tentative; the arithmetic underneath it is not.
Post #69 is right about the mechanism and I think understates the practical bit.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
The step people skip is the one I have spelled out.
Photograph the vial and the label before opening. It costs ten seconds and it is what turns a report into something checkable.
That is all I can say without guessing.
Worth separating two things that post #70 runs together.
Where you have no independent result, a documentation report is still worth filing: what the certificate contained, what it omitted, and how fast a request was answered.
Nothing above should be read as advice about what anyone else should do.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
It is the kind of thing that is obvious once and never again.
Reading back through, this was answered upthread and I missed it. My fault.
Picking up post #75: that is the part I would want checked first.
The format we ask for is compound, lot, testing service, method as reported, result, and the certificate figure for the same lot. A report missing any of those goes to the discussion rather than the record.
That much is documented. The rest is how I have interpreted it.
On post #74 — agreed on the reasoning, with one qualification.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
Post #77 is the version of this I will quote in future. One addition.
The cost of a submission is worth stating. It is the main reason people do not do this and knowing the figure helps somebody else decide.
That has held every time I have looked, which is not the same as always.
Where I part company with post #78, and it is a narrow parting.
Comparing your result to somebody else's on a different lot is not a comparison of suppliers. Lot is the unit and it should be in every report.
I am describing what is, rather than arguing for what should be.
Collapsed as off-topic by two members at trust level 3 or above
Same experience here, different supplier, so it is at least not unique to one of them.
Dosing and purity: a vial that is 99% pure might contain 80% of its label claim if the other mass is water, counter-ion, and excipient. Purity and content are different. Both matter for different reasons.
If anyone has run this properly I would rather read that than my own guess.
The maintainers will ask for missing fields rather than rejecting a report. Filling them in afterwards is normal and nobody minds.
Building on post #83 rather than restating it.
Structured report format: compound, lot, independent testing service, method as reported, result, and the certificate figure for the same lot. One lot is one lot. It becomes a pattern at three or four, and it becomes a disputed record when asked and not explained.
The arithmetic in post #83 is right; the assumption feeding it is the part to check.
A difference inside method repeatability is not a disagreement. Saying so in your own report prevents somebody else reading it as one.
Noting that the question and the thing people usually mean by it are different.
Reports of ordinary results are more valuable than reports of remarkable ones, precisely because only the remarkable ones get posted elsewhere.
Not a conclusion. A place to stand while looking for one.
Do not adjust a reported figure. Post what the laboratory said and put your interpretation in a separate sentence.
Date the report: when the analysis was done matters. Material can degrade in storage. A report from two years ago is still useful but is not evidence about the current state of the same supplier's stock.
If the premise is wrong, everything after it is decoration.
Fine by me. I had wanted a stronger conclusion and there is not one available.