Infrared spectroscopy expert witnesses may advise regarding spectroscopic analysis, infrared spectroscopy, atomic absorption spectroscopy, and related topics. Here the American Society for Mass Spectrometry defines mass spectrometry:
Mass spectrometry is a powerful analytical technique that is used to identify unknown compounds, to quantify known compounds, and to elucidate the structure and chemical properties of molecules. Detection of compounds can be accomplished with very minute quantities (as little as 10-12g, 10-15 moles for a compound of mass 1000 Daltons). This means that compounds can be identified at very low concentrations (one part in 1012) in chemically complex mixtures. Mass spectrometry provides valuable information to a wide range of professionals: physicians, astronomers, and biologists, to name a few.