Wow this is the coolest thing. I was looking at trying to build a DIY raman spectroscope and you can make one of those for under 100$ [1], but near-IR spectroscopy opens up more possibilities for sure. From what I understand (I'm not a scientist but I love the idea of having access to these tools) raman spectrscopy is limited to asymmetric crystalline molecules, so you can't really get a good reflection off of say salt to get a reading. (Edit - Looks like Near-IR is complimentary - "Raman active vibrations aren’t visible in the infrared for molecules with a symmetrical stretch. Similarly, infrared active vibrations aren’t visible in the Raman spectra for molecules with asymmetric stretch. This is known as the Principle of Mutual Exclusion and is what makes NIR and Raman Spectroscopy complementary techniques." [2] ) What we're really hoping to find out is if we can detect stuff like pthalates in plastics and heavy metals such as cadmium in metal products, I understand we'll probably just want to send things off to a lab to get GC/MS done for those things after talking to some people who have more experience than I do but I still want to see if I can build a bunch of these raman or near-IR spectroscopes for pharmacies in the third world. Counterfeit drugs are a real problem out there and they don't need to be.

[1] https://www.hackteria.org/wiki/images/a/a0/MobPhone_RamanSpe...

[2] https://www.labmate-online.com/news/mass-spectrometry-and-sp...