Mass spectrometry space applications

A number of other laser spectroscopic techniques are of interest but space does not permit their discussion. A few specialized methods of detecting laser absorption worthy of mention include multiphoton ionization/mass spectrometry (28), which is extremely sensitive as well as mass selective for gas-phase systems optically detected magnetic resonance (29) laser intracavity absorption, which can be extremely sensitive and is applicable to gases or solutions (30) thermal blooming, which is also applicable to very weak absorbances in gases or liquids (31) and... 

The gas phase limitation imposed by the very nature of the GC-MS experiment limits its applicability to chemical space. The Venn diagram in Fig. 19.4 illustrates an approximate mapping of applicability of the combined chromatography-mass spectrometry techniques discussed here. Using only relative molecular mass and polarity as two dimensions that can map chemical space, the figure indicates that the applicability of GC-MS is limited to those relatively small, thermally stable, nonpolar compounds that can be readily volatized (or made to volatilize by derivatization [26]) to pass through a gas chromatographic column. 

Borusiewicz, R., Zadora, G., Zigba-Palus, J. Application of head-space analysis with passive adsorption for forensic purposes in the automated thermal desorption-gas chromatography-mass spectrometry system. Chromatographia 60, 133-142 (2004)... 

The applications of molecular mass spectrometry are so numerous and widespread that describing them adequately in a brief space is not possible. Table 20-.5 lists... 

Tandem mass spectrometry (MS/MS) has attained an enviable status as an analytical tool to identify and quantify compounds in complex mixtures. MS/MS refers to the coupling of two stages of mass analysis, either in time or space. Of all the ionization techniques, only electron ionization (El) provides abundant sttuctural information. To obtain additional structure-specific information by other ionization techniques, it has become essential to perform MS/MS experiments [1,2]. MS/MS was first used in the late 1960s [3]. Since that time, its applications and popularity have continued to grow. Its major contributions are in the fields of structure elucidation of unknown compounds, identification of compounds in complex mixtures, elucidation of fragmentation pathways, and quantification of compounds in real-world samples. In recent times, several new generations of instruments have become available for tandem mass spectrometry applications. Basic concepts of tandem mass spectrometry and an account of these new developments are presented in this chapter. Additional reading material is listed at the end of the chapter. 

To date, a number of articles have discussed the use of mass spectrometry (MS) for space applications [1,ISIS]. In this chapter, our objective is to give a comprehensive and up-to-date review of various MS instruments and the complementary GCs that have been employed in the past or ongoing planetary missions. In Section 17.3, we discuss the application of GCs in solar system exploration followed by a chronological introduction to spaceflight mass spectrometers employed in major planetary missions (see the summary in Table 17.1). 

---