Raman Spectroscopy is a laser-based technique used to identify bulk* chemical compounds without touching or destroying the sample. A known-energy source, such as a 785 nm red laser, emits what are called excitation photons that interact with a substance’s chemical bonds – molecular vibrations resulting in energy transfer and scattered photons
Colorimetric testing is an analytical technique that is what one might guess it is: a chemical reaction that produces a visible color change
Solid Phase Micro Extraction or SPME (say “spee-mee”) is a chemical extraction/sampling technique that allows the direct adsorption of many trace volatile and semi-volatile organic compounds onto a specially coated fiber