I did a COA for some crude we were running a few months back, and it came back positive for 2 pesticides. Needless to say, had to buy new flasks, full clean up, destruction of distillate etc.
I sent a new sample in a few days back, and I pulled the previous COA (for the pesticide stuff) and now the lab result shows no pesticides. I called them and emailed them, but no answer to why this happened.
I kept the old and the new COA (luckily).
Is this a “normal” thing?
mistakes happen.
pesticides don’t just disappear.
any time you fail, you should retest.
ideally with a second lab.
you destroyed distillate without testing it?
yet kept crude around & had it tested again?
not sure that adds up…
This is why we do not run compliance testing first. Next time just ask for an R&D test so it’s not reported and you will have a shot at retesting/remediation.
We got some new biomass which we are running, so we got new crude. I did do R&D tests and we did run it through a second lab which came back with positive for pesticides.
My worry is that the lab changed the COA. Would you trust a lab like that in the future?
I spoke with the lab and they said the levels were so low that they reran it and it came out negative. He was however concerned that it was a false negative and offered a free retest if I could find some more of that crude.
The concern I have is that I was not notified of a second rerun of my sample and that the results had changed. Is that common for other labs to do?
Not if they never reported the change to you, the customer that the change impacted.
Any quality analytical chemist will rerun surprising samples at least once, and really three or more times with potentially multiple sample preps. Otherwise hard to know if the results are to be trusted.
With the quality of canna/hemp analytical labs I would expect that to be unusual tho
What pesticides? Some pesticides are short lived. Example: Naled will decompose to dichlorvos in no time under certain conditions.