thats not great
#test-results 2025-12-02
Tuesday44 messages10 participantstimes are UTC
Highlights from this day
- verify_or_dont — is anyone tracking results over time in a way they would share 20:23
- area_percent — right so my sheet has 8 lots from WWB with a spread under a point, which is tight 20:43
- area_percent — anyone had a result they think was a lab error rather than a bad vial 20:50
- coa_or_cope — my vial assayed under label but the purity was fine, which matters more 21:15
- HPLC_Hank — 99.2 against a certificate of 97.4 is fine. the same supplier landing low four times in a row is a question 22:52
log the boring results too. a channel that only records failures produces a false picture
i have never regretted spending the money on a test. i have regretted not testing twice
[edited]do the results in this channel skew because people test when suspicious
is it worth testing if the vial has already been through a warm transit
i told TFC about a result they would not have liked and they did not argue. credit where it is due
update from 20 months ago: retested the same supplier, result came back better, logged both
post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
*VendorInvestigate not the other one
certificate said 99 and the independent came back 96.8, is that a problem
is anyone tracking results over time in a way they would share
janoshik-sg-1177.pdf
2 pages · 916 KB · not retained in the public archive
the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
log the lot number
weigh the vial before you reconstitute. it costs nothing and catches the common failure
anyone tested the same lot twice at different labs
[edited]right so my sheet has 8 lots from WWB with a spread under a point, which is tight
🤝8
how much does sample handling on my end affect the number
anyone had a result they think was a lab error rather than a bad vial
❤️5💀10
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
[edited]what interests me is when the gap goes the same direction every time. once is noise, three times is a pattern
if the vial has been through a bad transit you are testing the transit as much as the supplier
is quantity testing available as a separate thing or bundled
underfill is more common than impurity. if you only test purity you are testing the less likely failure
attach the pdf
weigh it first
a point or two between the certificate and an independent result is inside what two labs disagree by
my vial assayed under label but the purity was fine, which matters more
lot bought purity assay/label
A-2418 2025-03 99.1% 9.6 / 10mg
A-2601 2025-08 98.7% 9.8 / 10mg
B-0114 2026-01 99.3% 9.4 / 10mg
B-0329 2026-04 98.9% 9.9 / 10mgwhen did you buy it
❤️1
underfill is more common than impurity. if you only test purity you are testing the less likely failure
97.4 against a certificate of 98.6 is fine. the same supplier landing low four times in a row is a question
On this day 5 years ago this channel logged 61 messages.
if you are testing to settle an argument you will not settle it with n of 1
quantity testing is usually a separate line item and it is the one worth paying for
log the boring ones
thats within range
ok so posting my VendorInvestigate result on lot KP-0925, what do people make of it
selection bias
thats a fill problem
which lab
fridge-thermometer.png
800 × 800 · 175 KB · not retained in the public archive
my result contradicts the supplier certificate, do i tell them
how do you post a result so it is actually useful to somebody in a year
a supplier disputing a result is rare here and it has never gone well for the supplier
assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem
99.2 against a certificate of 97.4 is fine. the same supplier landing low four times in a row is a question
👍1🤝10
Recon calculator: 10mg in 1.5ml = 8mg/ml.
nice result