gross mass on a jewellery scale plus the water content is enough to catch most underfills
#coa-reading 2026-06-26
Friday22 messages7 participantstimes are UTC
Highlights from this day
- endotoxin_ed — a vial can be 99.4% pure and hold 8.1mg of a 10mg label. both numbers are true and only one of them is the one you care about 20:44
- deamidation — quick one a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully 21:31
- deamidation — i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does 21:34
- VialBot — Batch lookup KP-0925: 5 independent reports on file, earliest 2026-02-07. 22:14
- gus_charts — for the archive why do some certificates report to one decimal and some to two 22:42
thats the counterion
whats the related substances table actually telling me
residual solvents matter more than people think for anything that went through a lot of purification steps
[edited]sloppy not sinister
[edited]check the lot
is water content normally on a certificate or do you have to ask
an identical chromatogram on two different lots is the single biggest tell there is
a vial can be 99.4% pure and hold 8.1mg of a 10mg label. both numbers are true and only one of them is the one you care about
is area percent the same thing as how many mg are in the vial
thats a tell
two certificates from the same supplier have an identical chromatogram, is that normal
quick one a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully
i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
[edited]the font on this one changes halfway down, am i being paranoid
no lot number on this certificate, does that make it worthless
does anyone keep a folder of certificates to compare over time
Batch lookup KP-0925: 5 independent reports on file, earliest 2026-02-07.
✅1
the retention time on this one is different from the last lot, problem
for the archive why do some certificates report to one decimal and some to two
peak RRT area% note
1 0.42 0.31 solvent front
2 0.88 0.44 related substance
3 1.00 98.72 main
4 1.14 0.53 related substancenet not gross
if you only read one line on a certificate, read the lot number. if you read two, read the assay