TV series featuring mega cool coroners and forensic scientist like „Qincy“, „CSI Miami“, and „Bones“ impressively demonstrate the power of modern instrumental analysis. Do they, really? It seems as if the desired relevant information would immediately be printed out as a neat report as soon as someone has a drop of blood, a trace of a lip stick, a tiny particle of whatever origin to by analyzed on one of these miraculous machines. Fully automated, easy-to-use, – simply phantastic.
Well, that is not the full story. Such analyses require great care from sample collection at the crime scene, to sample preparation prior to analysis, and when finally running the measurement. And then, there should be an expert to interpret the data. Of course, some applications like drug screening can be standardized, but still, this requires that a method has been developed and validated before it can be used.
Qualitative analysis (what is it?) is easier to accomplish than quantitative results (how much of it?). Also, there is no single lonesome researcher sitting in red and blue lit laboratories. Rather, there is a team of many experts working in rather usual chemical, microbiological, microscopic, …, laboratories.
In environmental trace analysis the situation is quite similar. One needs to focus on the target compound while at the same time eliminating the (uninteresting) matrix, e.g., to find PCBs in waste engine oil, traces of pesticides in drinking water or food, or residues of poisoning in body fluids. It is mandatory to selectively analyze a set of target compounds at ppm (parts-per-million) or ppb (parts-per-billion) level. This is why we are facing the problem of designer drugs. The criminals are modifying the drug as to suppress the detection, typically by changing a molecule’s mass via the addition of a substituent, e.g., substituting an H by CH3 shifts molecular mass by 14 u.
It also depends on wherein one needs to detect a compound or compound class. Are we looking at pesticides on orange peel, in drinking water, in waste water or in soil? The task becomes increasingly difficult as the complexity of the matrix increases. While it takes a method of element MS to detect arsenic in hair it calls for organic mass spectrometry to find cocain in the same biological sample.
Just do not believe because it has been shown on TV. The brighter and more sensational the news the more likely are superficial treatment, oversimplification, error, or simply blunt fake.