ABSTRACT
The mass spectrometer, in combination with a chromatographic inlet system, is probably the most powerful and most useful tool available to the environmental analyst. As we have seen, chromatography is an efficient separation technique which uses a variety of sensitive and selective detectors to analyze a wide array of compounds. However, these detectors do not provide much information about the molecules being detected. In chromatography, the retention time is the major piece of information used to identify a compound. I f two compounds have very close retention times, identification becomes very difficult. The mass spectrome ter, however, provides information about the structure of the molecule. In a mass spectrometer, a molecule is ionized and fragmented, then the molecular mass of each fragment ion is determined. Each molecule forms a unique set of frag ments, so the mass spectrum shows a pattern which can be considered as a fingerprint of the molecule.
