Lab results: Reference Recovery

First post here. I just found this fantastic community yesterday.

I’ve been coming across a lot of lab results lately with reference recoveries up to 104%. What are the reasons for >100% extraction recoveries? Maybe the machines aren’t calibrated correctly? Logically, it makes sense that there is a confidence interval here, and that there’s a certain SD for these machines. Both reports read: “method detection limit is generally considered to be 3x SD.” but they don’t mention what the SD is.

While these results look precise, how can they be considered very accurate if the reference recovery varies by 5%?

Most likely because the sample was more pure than the standard used to calibrate the machine.

Could also be because the calibration was not done correctly such as using a slightly wrong concentration or fucking up the standard curves.

The dilutions and calibration should account for the sample being higher than the standard. That isn’t a huge problem.

I am pretty sure these labs are all biasing results upward, whether on purpose for business reasons, or accidentally due to cutting costs or ignorance.

THCA is not completely stable. Let your standard degrade or absorb moisture coming out of the freezer and results will be biased upwards the same percent the standard is degraded. This is a giant problem with lab testing that requires significant time and money to get right, especially for so many different unstable analytes.

Theres also error in weighing and dilution and for reference recovery, even more error. The fact that they are showing reference recovery at all is a good thing. I’d like to see chromatograms that show how the results were calculated.and how the peaks were integrated. These instruments aren’t magic boxes that spit out a number, they need qualified people spending some time on each sample.

These results honestly look pretty good compared to a lot of labs out there. Think of it like 104% +/- 10%, meaning the real result is likely 94-99%. You can get it down to +/- 0.1% but it will almost always be cost prohibitive for weed, other than small r&d.

If you repeat the procedure enough times on a 1g sample, you can end up with mountains of THC that you can get rich from. I think. 4% increase, compounded…

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