"Capsaicinoids are the name given to the class of compounds found present in members of the capsicum family of plants. The most common of these compounds is
N-Vanillyl-8-methyl-6-(E)-noneamide, or
Capsaicin for short (View a model of this molecule using
Chime or
VRML plugin). Nearly as common is
Dihydrocapsaicin (
Chime or
VRML). These occur in varying ratios from plant to plant, from a 1:1 ratio to 2:1. Between them they typically make up 80-90% of the total capsaicinoid concentration, the rest being made up by such compounds as Nordihydrocapsaicin (
Chime or
VRML), Homocapsaicin (
Chime or
VRML), and Homodihydrocapsaicin (
Chime or
VRML)."
Just as cannabis has different cannabinoids (THC, CBC, CBD, etc) chiles contain different levels of the different capsaicinoids. These compounds effect the mouth differently so some chiles have a quick smack you in the mouth heat, others are a slow creaping burn, etc.
From discussions I've had with labs, they have to have a machine that is calibrated for capsaicinoids, they also need to know how to read the results, what to look for, and how to process the samples. Some labs I've contacted have told me they don't do SHU testing, they aren't set up for it, whatever. While college and university labs can do a lot of food related tests, like pH, SHU testing is not a standard test for all labs.
One
troll person who thought they knew more than 3 labs and had access to a HPLC machine, did a test and said Pure Evil 9.6mil wasn't even 5milSHU, claimed I was ripping people off, false advertising. I've had about a dozen Pure Evil and related products SHU tested by 3 labs that are experienced doing SHU testing and all the items came back with SHU results at or above their stated SHU levels. I think I trust a lab that's been doing HPLC pungency testing for 30 years and does SHU testing for the Chile Pepper Institute in NM as well as dozens of fresh chile growers/processors than some moron who works for a chemical company.