whats the worst result anyone has logged and what happened next
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#test-results 2026-04-02
Thursday36 messages6 participantstimes are UTC
Highlights from this day
- monoisotopic — whats the worst result anyone has logged and what happened next 16:27
- hydrate_hana — the honest limits: hobby chain of custody is weak and any result here should be read with that in mind 16:28
- triple_ag_tom — the widest spread in my data is about 2.6 percentage points across five lots from one supplier 17:18
- triple_ag_tom — underfill is more common than impurity. if you only test purity you are testing the less likely failure 17:26
the honest limits: hobby chain of custody is weak and any result here should be read with that in mind
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weigh it first
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how much does sample handling on my end affect the number
does a bad result on one lot condemn the whole supplier
[edited]whats the lot
when did you buy it
do you test every order or sample it
quantity testing is usually a separate line item and it is the one worth paying for
certificate said 98.1 and the independent came back 98.6, is that a problem
[edited]a single sample tells you about a single vial. that is genuinely all it tells you
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the widest spread in my data is about 2.6 percentage points across five lots from one supplier
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has a supplier ever disputed a result posted here
whats the underfill rate people are actually seeing
nice result
underfill is more common than impurity. if you only test purity you are testing the less likely failure
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how do you separate batch variance from supplier variance
is a purity-only test worth the money if underfill is the common failure
my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ
if the vial has been through a bad transit you are testing the transit as much as the supplier, ymmv
attach the pdf
i had a result i am fairly sure was a handling error on my side and i logged it as such
96.8 against a certificate of 98.1 is fine. the same supplier landing low four times in a row is a question, anyway
thats a fill problem
test it again
log the boring ones
a result without a lot number and a purchase date is an anecdote with a pdf attached, n of 1 obviously
is quantity testing available as a separate thing or bundled
unrelated but post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later
anyone had a result they think was a lab error rather than a bad vial
selection bias
anyone tested the same lot twice at different labs
[edited]i have never regretted spending the money on a test. i have regretted not testing twice
quick one is anyone tracking results over time in a way they would share
how many lots do you need before you can say anything about a supplier
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does anyone log the negative results, the boring ones