ABSTRACT
At the time of the release of the toolbox in 2003, GC/MS was used as a powerful tool to assist in identifying unknowns, in part due to decades of development of GC/MS technology, mass spectral libraries, and necessary software. Further, unlike GC/MS that had extensive, transferrable mass spectral libraries, LC/MS did not have reliable libraries available to assist the analyst in identifying unknown compounds. Factors favoring the reliability of GC/MS libraries included a robust, comparatively simple (relative to LC/MS) interface design, high ionization energies, the use of a gas as the chromatographic mobile phase, and more than 50 years of history, scientic advances, and consensus about how to create GC/MS libraries. However, not all potential contaminants are amenable to GC/MS, whereas LC/MS has the potential to identify such compounds quickly, although caution in the application of these LC/MS techniques is recommended as they are subjected to a number of interferences.
