What am I vaping?

SilentRunner

SilentRunner

Well-Known Member
I got this new gas sensor and I was trying it out for the first time today. After I was vaping the sensor went from 500 ppm to 1300 immediately and is still on this level hours later.

https://www.cdiweb.com/ProductDetail/MICS6814-SGX-Sensortech-Limited/464975/pid=468

Detectable gases
• Carbon monoxide CO 1 – 1000ppm
• Nitrogen dioxide NO2 0.05 – 10ppm
• Ethanol C2H5OH 10 – 500ppm
• Hydrogen H2 1 – 1000ppm
• Ammonia NH3 1 – 500ppm
• Methane CH4 >1000ppm
• Propane C3H8 >1000ppm
• Iso-butane C4H10 >1000ppm

The sensor is measuring CO2 and other gases, but I don't think it is the CO2 it is picking up. Is there a gas analysis of what I am vaping (flowers)?
 
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OF

OF

Well-Known Member
SilentRunner said:
I got this new gas sensor and I was trying it out for the first time today. After I was vaping the sensor went from 500 ppm to 1300 immediately and is still on this level hours later.
Click to expand...

My guess is you've contaminated the surface with condensate and it doesn't like it. Perhaps you can wash it clean again with ISO, ETOH, Methanol or some similar solvent (or flat out destroy it trying?).

You're continuing to sense the gas trapped under that like it was a layer of paint?

I don't think it's intended for this sort of duty.

OF
 
SilentRunner

SilentRunner

Well-Known Member
I think the device works really well. Great value for 60$. If you have an Arduino and a lot of time you can buy the chip for 12$ and build a device yourself.

So this morning it still showed 1400 ppm. I opened the balcony just wide enough for my cats and within 20 minutes it was back to around 500 everywhere. I am surprised there is such a quick exchange. The rooms with doors opened total to 80 m². When I went into my child's bedroom it showed 6000.

I need to do more research on how these MEMS metal oxide sensors really work. I also want to know how GC/MS and HPLC really work to analyze the vapor. Do you have to know what you are looking for or does it tell you all the contents?
 
OF

OF

Well-Known Member
SilentRunner said:
I also want to know how GC/MS and HPLC really work to analyze the vapor. Do you have to know what you are looking for or does it tell you all the contents?
Click to expand...

The general answer is you get a spectrum of atomic masses. For instance reading normal air would give you a peak at 32 for Oxygen that's 1/5th as high as the 28 for Nitrogen (since air is about 20% Oxygen and 80% Nitrogen). CO2 with an atomic mass of 40 would be a tiny fraction of that. Oxygen is really 16 grams to the mole, and Nitrogen is really 14 but since both gasses come in pairs (O2 and N2), the weight of each molecule is doubled.

WRT vapor the stuff we want is much bigger of course. Signal to noise can be a problem, finding small amounts can be dicey. At the heavy end there are also artifacts to contend with sometimes. Broken bits of bigger molecules get counted.

There are advanced programs that make suggestions, of course, but you do have to have an idea what to expect or the adventure changes from 'how much?' to 'now what could that be?'.

Slide rules down....... Regards to all.

OF
 
G

Gazaam

Well-Known Member
SilentRunner said:
I also want to know how GC/MS and HPLC really work to analyze the vapor.
Click to expand...

HPLC (High Power Liquid Chromatography) separates the species of cannabinoids present by allowing them to diffuse (usually in a straight line) in a solvent or solvent pair. In this state, each molecule will have a specific diffusion velocity which is characteristic of the molecule, and the solvent(s). So if you have a mixture of two substances dissolved in a solvent, and one of them has a slower diffusion constant than the other, and you put a drop of the mixture on a diffusion surface (which could be as simple as a piece of blotter paper), then after a while the two substances will diffuse outward at different rates from the drop point and you will see bands. The simplest example is to put a drop of ink (water soluble ink i.e. fountain pen ink or non-permanent magic marker ink) in the center of a sheet of damp paper towel. If you come back later, you will see the banding effect.

The predecessor of HPLC is one of the simplest forms of chromatography: TLC (Thin Later Chromatography) which works pretty much as described above. Except the starting substance probably contains many different different cannabinoids, not just two. So after the flow has occurred, there will be a bunch bands representing the different cannabinoids in the mixture. But unlike with ink, the bands will not be visible. So after the diffusion has occurred, you spray a special dye on the paper and it colors all the cannabinoids red. Then you match your result up to several standard reference images and you can identify the presence of each cannabinoid by identifying its band and you can guesstimate how concentrated it is by how dark and big the red band is. There is even software that you can use to analyze the images of your TLC plates and quantify the individual bands for you. Here is a typical commercially available TLC test kit customized for cannabinoid determinations. {{{ https://www.alpha-cat.org/the-test/how-it-works/ }}}{

The nice thing about TLC is that it is really cheap to do, easy to master, fast, doable in your kitchen and pretty versatile. The kits are well under $100 and for less than about $3-4 hundred, you can build your own set up at home from scratch which results in dirt-cheap analysis results is the neighborhood of about $5 for ten samples run simultaneously side by side.

HPLC is like TLC on steroids. The upside is that can measure more stuff with much more precision than TLC. The downside is that the equipment is many many many thousands of dollars, takes up a lot of space and requires ongoing maintenance and calibration. So if you want to play with this stuff, and you are not doing fundamental research where you need to make highly precise and repeatable measurements, I would suggest you look at TLC.

Oh, and if you think that HPLC is expensive, GC/MS is ten times as bad. Basically, you would need to know someone working in a university environment who would be willing to run some samples for you after hours.
 
Gazaam,
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bossman

bossman

Gentleman Of Leisure
I've never heard of this sort of nerdery. Has anyone developed a testing kit for oils? That's where I'm asking myself "What am I vaping?" I'd love to know my concentrates are free of pesticides and solvents.
 
bossman,
G

Gazaam

Well-Known Member
Well, let's hope some of this "nerdery" may help prolong our FC colleagues' lives!!

Here is a typical commercially available TLC test kit customized for cannabinoid determinations:

https://www.alpha-cat.org/the-test/how-it-works/

It is mainly designed for testing cannabinoid contents. Although theoretically possible, it is doubtful that a TLC test would yield any meaningful info on pesticide or solvent contents. If there are any pesticides present, the amount would be so small that it would not be detectable by TLC, and probably not by HPLC either. If you are concerned about this, I suggest you secure small quantities of the strains you like to use from the growers you like to patronize and then send them to a lab for detection of nanogram quantities of pesticides in weed. Or, alternatively, either the grower or the purveyor of those strains may already have lab test results available.

Here in Canada, where pot is going to be legalized tomorrow (!!!), mail order marijuana businesses and most BC growers have been complying with Health Canada weed regulations for well over a year now, even before legalization was about to become a reality. These regulations specify maximum permissible pesticide levels, as well as maxima for several biological and potentially dangerous "pollutants" such as mold and certain bacteria.

So if you are buying weed in a region where it is regulated, you should have a pretty good governmental "safety net" in place with regard to those pollutants.

I would imagine that you can probably purchase some sort of a simple colorimetric test (i.e. you put a drop of some kind of a dye in an mL or so of ETOH extracted weed solution. If the pesticide is there, there will be a color change. These tests can be made incredibly sensitive due to their nature, and should be able to pick up nanoscopic quantities. I freely admit that I am extrapolating about the existence of these kits, but I presume that growers (including normal food farmers) would need something simple and easy to use like this to make sure their products are pesticide-free. Worth googling if you are interested.

With respect to solvents, the simplest safety measure is to use an oil that is made using non-toxic solvents, such as ethanol, limolene, etc.
 
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