Is there anyone here doing plant tissue / sap / etc nutrient analysis in-house?
I have bits and pieces including a spectrophotometer and a digestion heater block. I’m looking at the economics of additional apparatus to round this out to run various protocols simply. Thoughts appreciated.
Very curious how this project develops.
Designed spectral analysis optoelectronics for years, but lack the biology/chemistry understanding to bridge the gap. Definitely have thought about it. Unfortunately most of my effort is just getting decent grow skills and finished smoke to date.
The spectrophotometer, in this application, is relying on chemistry protocols that are selective for specific nutrients. N,P,K, Ca, Fe, etc. The chemistry, in essence, produces a colorimetric result that is then measured by the photometer. Not too unlike those garden PH kits where you add some soil, water, and a reagent then manually compare against a color chart. Just more precise, repeatable, and a larger library.
Some of the protocols require additional tools and then there’s the what are the best protocols to utilize. For instance, the plant matter can be dissolved in hot acid or can be run through a muffle oven to ash it. There are a bunch of protocols targeting specific elements, some more complex than others.
The general idea is that it is less expensive and less complicated than something like LC-MS. And, not relying on an outside lab. Expensive, slow turn-around, etc. At least, that’s the idea.
It could be used for other things as well. Here’s a tincture I ran through the spectrophotometer. Though, I haven’t really spent much time trying to analyzing whether there something useful in the results.
It’s just another one of those half-pieced together projects at the moment and trying to figure out what is still needed without over-spending.
Very cool, I’m highly intrigued by this stuff, so I’ll follow along .
This is way above my technical pay grade, but I see a lot of really geeked out lab stuff over at Future4200, if you’re not over there those guys are something else when it comes to the hustle culture but they’re smart:
Edit: this is their thread specifically about in-house analytics:
Oh right, forgot about them. They have some great discussions particularly re: extraction.
This one looks mostly like potency testing focused on using HPLC or GC (which would be another cool thing).
I’ll take a gander around. Thanks for the links.
It’s not a place I’ve ever figured out the characters beyond a single thread when reading about stuff but I find it a valuable resource for many things. Especially extraction like you said, but also they’re very good with hydroponics and automation, and nutrient program building and analysis from base salts. I think one of the site mods is the person behind the fulvic product that I use, Mr. Fulvic, which is sold commercially as AGT-50 by Agtonik, which is his username on there. They’re a company from Kalamazoo Michigan that water extracts an ancient humus deposit they control, the test numbers for their product vs other fulvic supplements are pretty off the charts! That’s where I found out about the stuff and read a lot of reports and tests from commercial growers that convinced me it was the key to growing with organics or salts as a chelator for everyday use, and a steady micronutrient source as well 
AFAIK cannabinoids are measurable in NIR, but in a wavelength that is expensive to measure (>1600nm). I haven’t looked into plant tissue though.
I have a set of Raman spectrometers I collected that are pulled from carotenoid detectors 405nm excitation. If it’s useful for this, let me know. I have some to spare.
You could probably do some fancy science with the Raman spectrometers. Those also, generally, utilize high-end lasers. High coherence, narrow bandwidth, stable wavelength, tunable (+/- a couple of nm). Probably includes a Peltier cooling device.
So much cool stuff to do …
I don’t think these are quite that fancy, but I have figured out how to use the spectrometer and they do have expensive notch filters on the input. Laser is fiber pigtail, and well heatsinked, but I don’t think they have peltier cooling iirc.
Use standard reagents for tissue, develop your standards from a single paid test. Send all your clients a color chart. Not that hard. Ammonia, Nitrate solute p and k should be in every garden maybe I’ll market an Amazon home leaf test kit.
