purity is not assay
#coa-reading 2025-09-03
Wednesday12 messages3 participantstimes are UTC
Highlights from this day
- two_three_lifts — unrelated but if you only read one line on a certificate, read the lot number. if you read two, read the assay 14:40
- plateau_pen — update from 11 months ago: started asking every supplier for water content and about half now include it, ymmv one decimal versus two is usually just house style, not… 15:26
- plateau_pen — i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does 15:32
- plateau_pen — 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 15:33
- plateau_pen — tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the mass balance 16:36
check the lot
⚠️8🤝1🎉12
good certificate actually
a certificate should name the method, the instrument, the column and the operator. most name none of those
tfa or acetate, how do i tell from the paperwork
unrelated but if you only read one line on a certificate, read the lot number. if you read two, read the assay
weigh the vial
two_three_liftsunrelated but if you only read one line on a certificate, read the lot number. if you…
update from 11 months ago: started asking every supplier for water content and about half now include it, ymmv
one decimal versus two is usually just house style, not precision
i was wrong about this for a year: area percent under-reports nothing, it just answers a different question than assay does
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
looks re-dated
tfa counterion runs higher by mass than acetate. if the certificate does not say, you cannot do the mass balance