an identical chromatogram on two different lots is the single biggest tell there is
#coa-reading 2025-06-11
Wednesday22 messages6 participantstimes are UTC
Highlights from this day
- VialBot — Testing queue: 9 submissions open, 115 awaiting dispatch. 19:15
- HPLC_Hank — the related substances table is the interesting part. a row of "not detected" means they did not look hard 19:16
- reta_resting_hr — i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does 19:30
- salt_bridge — a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully 19:59
retention time shifts between runs are normal. relative retention time is the number to compare
purity is what fraction of the contents is the target. assay is how many mg are actually there. different questions
thats a real table
Testing queue: 9 submissions open, 115 awaiting dispatch.
⚠️18
the related substances table is the interesting part. a row of "not detected" means they did not look hard
🔥6📉11📈8
does anyone keep a folder of certificates to compare over time
check the lot
i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
is water content normally on a certificate or do you have to ask
weigh the vial
🤝1
why do some certificates report to one decimal and some to two
thats the counterion
is there a standard layout or does every lab do their own
a lab that reports "greater than 98%" rather than a number is telling you they did not integrate carefully
✅10
no lot no certificate
two certificates from the same supplier have an identical chromatogram, is that normal
ask for water content
water content is why an honest 10mg vial assays at 9.1. karl fischer titration, and most certificates omit it
purity is not assay
is endotoxin ever tested on research material
same chromatogram