Here's a tiny bit of helpful background:
A good deal of a forensic chemist’s work is instrumental analysis, says Darrell Davis, laboratory director at the Drug Enforcement Administration’s (DEA) South Central Laboratory in Dallas, Texas. Davis has been a forensic chemist for over 29 years with DEA, originally on the bench analyzing samples for the presence of controlled substances at the Southwest Laboratory in San Diego, and later managing the DEA lab in Dallas.
Davis says that the DEA’s work is “mostly analytical [chemistry], both qualitative and quantitative. “We not only identify the controlled substance and its constituents … We also quantitate the controlled substance to let the courts and special agents know how pure the sample is. For example, we might analyze a kilogram of a cocaine-like substance and determine that 80% of that weight is pure cocaine.”
In order to do these analyses, the chemists in Davis’ lab use mass spectrometry, infrared spectroscopy (IR), gas chromatography (GC), and liquid chromatography (LC). “We also use NMR [nuclear magnetic resonance] on the more complex types of samples.”(The synthetic chemist in me wants to know - what's the other 20%?)
Anyway, anyone have any experience they'd like to share?