Hemp is cannabis for industrial uses, like the manufacture of cloth, paper or rope. Tetrahydrocannabinol (THC) is the cannabis ingredient that makes you stoned. Hemp contains so little that you could even pass a drug test after smoking it. It’s legal in the United Kingdom and all of these United States.
Even police dogs can’t tell them apart
Law enforcement has sometimes been confounded by the fact that hemp looks and smells just like regular cannabis. Even police dogs can’t tell them apart. New research, however, has discovered that’s it’s possible to use lasers to make the distinction quickly, affordably and very precisely. Until now, this required costly and lengthy analysis at a certified lab using high pressure liquid chromatography.
Carrying legal hemp can get you into a lot of trouble
A prime example of the difficulty of telling hemp and bog standard cannabis apart came in December 2019. This occurred upon the arrest of a Texas man because his vehicle contained over a ton of cannabis. He spent almost a month in a cell before lab results proved that he was carrying hemp and not marijuana. Prosecutors throughout the United States shy away from many cases of cannabis possession in the absence of convenient testing.
Behold! A study!
A study by researchers at Texas A&M University appeared in the journal RSC Advances in January 2020. It revealed that is was possible to tell the difference between hemp and regular cannabis with “100 percent accuracy” by using the hand-held laser device the Raman spectometer. Being hand-held and non-invasive, police could use it in the field.
So what is a Raman spectrometer?
Raman spectrometers are named after the Indian physicist CV Ramen, who identified the effect of sunlight on liquids in 1928 and earned a Nobel Prize for physics two years later. These spectrometers illuminate samples with a laser beam. A lens collects electromagnetic radiation from the illuminated point. A computer then decodes the signal.
How it was done
Fresh samples of hemp and regular cannabis were frozen, which doesn’t change their appearance or texture. Lasers could distinguish a “change of intensities” showing “structural differences between hemp and [marijuana] plants.”
Hemp contains more cellulose than its psychoactive sibling. It was the amount of delta-9 tetrahydrocannabinolic acid (THCA) in the samples that was measured. THCA isn’t psychoactive but transforms into THC when heated. Further laboratory testing is afoot “to determine accuracy and range” of the process.
It’s foreseen that Raman spectrometers will see use in future missions to Mars to analyse soil. Lasers were only invented in 1958. It would have been nice if this technique had been available in the days of George Washington. He definitely grew hemp, but he seems to have grown regular cannabis because he separated the male and the female plants prior to fertilisation. The only reason for so doing is to get a better high. Washington would have appreciated that, afflicted as he was by chronic toothache.