ABSTRACT
Advances in methods to introduce samples into IMS drift tubes as described in Chapter 4 have enabled the range of applications of IMS to be expanded beyond the measurements of volatile and semivolatile compounds normally associated with IMS. Molecules and samples, wholly new to IMS measurements, such as peptides, proteins, and carbohydrates, have been explored during the past decade and may have importance in medical research or clinical use. Such studies have been made possible in large part through the adaptation of methods of sample delivery or ionization that have been successfully pioneered in mass spectrometry during the past 20 years. These include electrospray ionization (ESI) for aqueous samples or matrix-assisted laser desorption and ionization (MALDI) for solid samples as discussed in Chapter 4. The importance of these methods in chemical sciences was recognized with the award of the 2002 Nobel Prize in Chemistry to John B. Fenn1 and Koichi Tanaka2 for developing them. The rationales for exchanging mass spectrometers with mobility spectrometers in biological measurements parallel those used previously with other measurements described in Chapter 6: mobility spectrometers are inexpensive, portable, and sensitive analyzers that use low power. What may be compromised in density of information in comparison to a mass spectrometer is rewarded with savings in cost and convenience. In other instances, IMS drift tubes can be combined with mass spectrometers as described in Chapter 5 for enhanced analytical capabilities in measuring biomolecules.
