Flow-injection analysis-mass spectrometry compounds

The high-throughput screening of combinatorial libraries can also be accomplished with flow-injection analysis (FIA)-MS [110], All operation steps of analysis, including input of the sample information, setup of the mass spectrometry analysis parameters, compound checking, and results reporting to the customer are automated. Samples are placed in a 96-well sample unit and analyzed by ESI-MS or APCI-MS. 

The most frequently chosen method for compound characterization in the pharmaceutical industry is LC/MS [6]. Replacing flow injection by a chromatographic separation prior to MS analysis offers three major advantages i) impurities or by-products are separated in time from the product of interest, rendering a purity assessment of the sample possible ii) ionization suppression of the compound of interest by salts, detergents, or by-products is avoided iii) the interpretation of mass spectra of pure compounds is much easier than the MS analysis of mixtures. Combinations of separation techniques with mass spectrometry have been reviewed recently by Tomer [39]. 

Figure 7.3. Analysis of a 50% ethanol untoasted oak wood extract GC/PICI reconstructed ion chromatogram of benzene compounds [M+H]+ signals. (54) anisaldehyde (m/z 137) (35) eugenol (m/z 165) (37) vinylguaiacol (m/z 151) (45) vanillin (m/z 153) (55) methoxyeugenol (m/z 195) (50) syringaldehyde (m/z 183) (56) trimethoxy-phenol (m/z 185) (53) coniferaldehyde (m/z 179). Internal standard-i.s. 1-heptanol (m/z 55). Analytical conditions PEG fused silica capillary column (30m x 0.25mm i.d. df 0.25 pm) injection port 240°C volume injected lpL (splitless) program oven temperature 3min at 70°C, 2°C/min to 160°C, 3°C/min to 230 °C, 25 min at 230°C transfer line temperature 280 °C carrier gas He at constant flow 1.3mL/min. (Reprinted from Journal of Mass Spectrometry 42, Flamini et al., 2007, GC/MS-Positive Ion Chemical Ionization and MS/MS study of volatile benzene compounds in five different woods used in barrel-making, pp. 641-646, with permission from John Wiley Sons, Ltd.)...

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