Chapter 2 Fourier Transform Ion Mobility Spectrometry for Detection After SFC

Abstract

This chapter discusses Fourier transform ion mobility spectrometry (FTIMS) for detection after supercritical fluid chromatography (SFC). It is one of the simplest of the hyphenated techniques and it is the only analytical method in which qualitative information can be obtained from ionization processes at atmosphere pressure. Based on gas phase atmospheric pressure electrophoretic separation of ions, IMS serves as a complementary technique to UV/Vis absorption and fluorescence methods of detection. The multifarious nature of IMS makes it difficult to discuss concisely the analytical figures of merit (FOM) for all operating conditions. Additionally, multiple mobile phase options may also alter response characteristics. Presently, a fully optimized FTIMS instrument for SFC has not been produced and questions concerning detector design and engineering as well as fundamental questions of ion mobility and chemical reactions remain unanswered. Nevertheless, the current state of the art of FTIMS offers considerable advantage for detection after SFC. Detection limits, mobile phase compatibility, and response versatility exceed most inexpensive detection methods available for SFC. Moreover, ion mobility data can be used to suggest unknown identities and when matched with chromatographic and ion mobility data from standards, confirmation of identifications can be achieved.