General principles and history

Detailed information on the composition of mixtures is crucial in many areas of modern life. Chromatographic techniques are one of the key techniques applied to answer questions on what is in a mixture and how much of each constituent is present. Gas chromatography (GC) is a very powerful separation method that can separate highly complex mixtures into its constituents, but unambiguous identification is difficult to obtain without the coupling to a sensitive mass spectrometer (MS). For optimum performance of hyphenated GC-MS, the requirements and performance characteristics of both techniques need to be considered and properly balanced. In this chapter the various parameters that are relevant for the coupling of GC and MS will be defined. In the hands of a well-trained analyst the technique is today more powerful than it has ever been.