one data point
#test-results 2026-02-24
Tuesday24 messages5 participantstimes are UTC
Highlights from this day
- LC_MS_Lena — a single sample tells you about a single vial. that is genuinely all it tells you 18:44
- VialBot — Inter-lab diff for lot D-0718: 98.1% vs 98.6%. Within expected range. 19:11
- coa_or_cope — my sheet has 9 lots from SGN with a spread under a point, which is tight 19:50
- two_four_ceiling — the results in this channel skew because people test when they are suspicious. that is selection bias and it is real 19:51
- LC_MS_Lena — has a supplier ever disputed a result posted here 20:53
weigh the vial before you reconstitute. it costs nothing and catches the common failure, your mileage will differ
a single sample tells you about a single vial. that is genuinely all it tells you
😂9🤝10
weigh it first
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
is anyone tracking results over time in a way they would share
Inter-lab diff for lot D-0718: 98.1% vs 98.6%. Within expected range.
update from 9 months ago: retested the same supplier, result came back better, logged both
[edited]quantity testing is usually a separate line item and it is the one worth paying for, for what its worth
[edited]a point or two between the certificate and an independent result is inside what two labs disagree by
thats within range
my sheet has 9 lots from SGN with a spread under a point, which is tight
📉2⚠️14
the results in this channel skew because people test when they are suspicious. that is selection bias and it is real
[edited]👍5
a result without a lot number and a purchase date is an anecdote with a pdf attached
nice result
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 / 10mg📈13
the widest spread in my data is about 2.6 percentage points across five lots from one supplier
Digest for the week of 2025-06-16 has been published.
coming back after 26 months with a follow up result, where do i put it
log the boring ones
if the vial has been through a bad transit you are testing the transit as much as the supplier
right so one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
thats a fill problem
has a supplier ever disputed a result posted here
🙏4🔥16✅11
selection bias