#test-results 2025-01-04

test it again

log the boring results too. a channel that only records failures produces a false picture

if the vial has been through a bad transit you are testing the transit as much as the supplier

while im here one bad test does not condemn a supplier. one good test does not clear one. both halves get ignored equally
underfill is more common than impurity. if you only test purity you are testing the less likely failure

if you are testing to settle an argument you will not settle it with n of 1

coming back to this post the lot, the purchase month, the lab, the number, and what you were expecting. that makes it useful later, ask me again in a month
a result without a lot number and a purchase date is an anecdote with a pdf attached

my read after three years of this: purity is mostly fine across the market and fill consistency is where suppliers differ

sample handling on your end absolutely affects it. draw cleanly, ship fast, do not let it sit warm

i test roughly every tenth vial. it is a sampling strategy, not paranoia

coming back to this how do you separate batch variance from supplier variance

99.4 against a certificate of 98.1 is fine. the same supplier landing low four times in a row is a question

log the lot number

is a purity-only test worth the money if underfill is the common failure

quick one is quantity testing available as a separate thing or bundled

how do you post a result so it is actually useful to somebody in a year

i have never regretted spending the money on a test. i have regretted not testing twice

the results in this channel skew because people test when they are suspicious. that is selection bias and it is real

my sheet has 4 lots from CPC with a spread under a point, which is tight

which lab

a supplier disputing a result is rare here and it has never gone well for the supplier

thats a fill problem

a point or two between the certificate and an independent result is inside what two labs disagree by

a result without a lot number and a purchase date is an anecdote with a pdf attached

thats not great

whats the lot

attach the pdf

has a supplier ever disputed a result posted here

how many lots do you need before you can say anything about a supplier

the honest limits: hobby chain of custody is weak and any result here should be read with that in mind

assay under label with good purity means you got less of the right thing. that is a fill problem, not a synthesis problem