Yea we use for early sexing. To be 100% honest we grabbed it as a way to practice on site sexin. I wasn’t comfortable committing to a new 96well qpcr machine. It wasn’t till coming here I realized you could buy used lab equiptment. Grabbing the 96 well for that price would of been a much better choice. normally we run 12 test batches so having to run the minipcr twice is a time killer.
Its more expensive per sex test than say mailing it in but once we expand to other tests (thc/cbd alleles) the cost per plant test comes down considerably.
We have an SRI Model 420. It is a really cool idea… Built in hydrogen generator so you don’t have to pack around a cylinder of Hydrogen if you want to take it out to multiple facilities and do onsite testing, “Internal Standard” (Methyl Stearate) so you don’t have to spend money on expensive standards… etc. I found after LOTS of trial and error and many phone calls to SRI that I was unable to produce consistent test results with it though. I would see variations as big as 10% from test to test on the same sample. After many frustrated days spent trying to dial it in, I finally gave up and opted to just purchase R&D tests from our lab at $75 a pop. I have nothing against SRI and it could definitely be a problem with operator error… Just thought I’d share my experience.
I have found all of the technicians I’ve trained on my SRI have started out fairly inconsistent. 10% error seems about right. if I was doing 3rd party testing I’d actually need to provide OR with each of their stats.
unless I use magnification on the syringe, there are definitely small bubbles that are contributing to this error rate.
The state certified labs here in OR are allowed a 20% margin between replicates before I’m allowed to call bullshit, so 10% isin’t as bad as it sounds.
It makes it hard to know who is right. Your GC or the lab.
This GC has the built in air compressor and I got a third party H2 generator. Right now I am the only person who will be using it so any deviation is on me. Not to worried, ball park is good. \
When you say 10% deviation your talking 99% down to 90%? That’s a fairly significant swing. I will probably run tests x3 or 4 and average.
Only like 3k into the whole thing so its gonna be worth what I paid
the only way to do it right is to do it yourself…which means if you know your own error rate, having repeatedly injected the same sample 10x and asked excel how good you are, then you can know who is right. or at least redo your injection, and then know.
so long as you don’t remove the column from the detector, or change the hydrogen flow, the FID response is incredibly stable. I’ve loaded 4 year old calibration files and gotten reasonable numbers. I’ve currently got everything calibrated with CBD isolate. which came to me labelled 98% pure.
I haven’t done a thorough comparison to our current 3rd party lab, but was dialled in nicely to our previous lab.
yes. if you examine the syringe you’re injecting with, I think you’ll understand why injection is probably the biggest source of variation.
if you’re looking a flowers, the variance between flowers on the same plant is a huge eye opener.
oh yes, flower is always variable. I am a bit bummed about the column issue. I also bought terp standards and terp columns. I am not sure I will use them now…
The GemmaCert is selling for less than $3k, assuming it’s not vaporware. also IR based. currently lists “total” THC & “total” CBD, which I assume means no resolution of the acidic from decarbed. Which seems off, given that everyone else doing IR is resolving those. they also look to have a $ per test scheme they’re planning to implement. suggesting the actual analytics might be web-based.
I met them in San Jose at the T&T conference a few months back. The bit I got to spend with them was interesting. I’m so far in the preliminary stages of my project that the details of the in house analyzer are not priority.
So…Big Sur Scientific has had 5 days to follow the link I provided them.
Guess I’ll do that paraphrase:
Much like the other non-distructive units (eg Sage, GemmaCert) they’re using IR.
what differentiates them is they will build a custom profile for your material. They claim this gives them the ability to quantify terpenes in flower and extracts. Without a standard (or even a solid ID yet), quantifying Δ10/10a THC would not be possible but if Δ10/10a is an issue for you, there are probably some tricks that could be played to at least bring it to your attention.
they’re more expensive that their competitors… and charge for those profiles.
Had a question come to me regarding sugar analysis…here was my reply (inadvertently off-list):
If I understand you correctly, you’re looking for a way to assess the ‘completeness’ of an enzymatic cellulose to fermentable sugar conversion. Seems to me there should be some inexpensive ways to do this that come out of brewing tech…like fermentation hydrometers (measure specific gravity/density where one compound is the main contributor, like glucose/sucrose), or refractive index devices, like this one:
Hope this helps…I detoured myself looking for more specific sugar analytical methods, so I might be able to get a handle on sugar extraction with ethanol. We get gross deposits like this in our WF if we don’t do brine washes (Ugh!). These deposits are hard (read: brittle), water soluble, sweet (yes, I did taste them!), and really foul up our WFD. I’m targeting them for derivatization, so I can identify them by GC/MS.
I’ve been using an HP 6890 GC-FID with a method from Restek. I was wondering what methods others are using because I don’t feel too confident about my results.
HPLC is the way to go for the quantification. It’s fairly expensive and solvent dependent which is why I went wuth GC. Realistically in house testing is for my own process improvements so I will just run three tests and average the results.
Just saw the SRI 420 today. For $4k I’d say it was the best bang for your buck and I can see setting folks up with them. What I saw suggests a longer column could certainly be hacked in on top of the fid to get better resolution.
