Liquid injection field desorption ionization

Numerous analytes could be good candidates for FD-MS, but undergo immediate decomposition by reacting with ambient air and/or water under the conditions of conventional emitter loading. Inert conditions such as emitter loading in a glove box does not really avoid the problem, because the emitter still needs to be mounted to the probe before insertion into the vacuum lock. Furthermore, the tuning of an FD ion source usually has to be optimized for the emitter actually in use which is not practicable with the sample already loaded onto its surface. 

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Liquid Injection Field Desorption Ionization Mass Spectrometry 545... 

Figure 14.2. Arrangement of an activated emitter in a liquid injection field desorption ionization (LIFDI) system. Courtesy of Linden ChroMasSpec GmbH, Leeste, Germany.

Griep-Raming, J., and Linden, H. B. (2005). Fully automated liquid injection field desorption/ ionization (LIFDI) mass spectrometry for high throughput screening of compounds with various polarity. 38. Annual DGMS Conference, Rostock, Germany. 

Gross, J. H., Nieth, N., Linden, H. B., Blumbach, U., Richter, F. J.,Tauchert, M. E.,Tompers, R., and Hofmann, P (2006). Liquid injection field desorption/ionization of reactive transition metal complexes. Anal. Bioanal. Chem. 386, 52-58. 

Fig. 7.1 Pieture of a liquid injection field desorption ionization probe tip (LIFDI-MS). (Reprinted from [9] with kind permission from Springer Seienee and Business Media)...

Because of the experimental difficulty of the technique and because more user-friendly and to some extent more powerful alternatives have become available, FDI is not frequently applied anymore, except for some specific applications. In this respect, an important development is liquid injection field desorption ionization (LIFDI), which enables sample application to the emitter without breaking the vacuum (see Fig. 7.1) [7, 8]. The specific applications where FDI and LIFDI are still applied comprise the analysis of some oiganometallic compounds [9,10], ionic liquids [11], and compound classes, such as (cyclo)paraffins, aromatic hydrocarbons, and nonpolar sulfur compounds (thiophenes) [7, 12-14], not readily amenable to ESI or MALDI. For such nonpolar analytes, mainly molecular ions M+ are observed, whereas for some more polar compounds, [M+H]+ and/or sodiated molecules ([M-l-Na] ) may be observed, e g., for glycosides (Sect. 7.5.2), lipids (Sect. 7.5.4), and peptides (Sect. 7.5.5). A detailed overview on technology and applications of FDI-MS was provided by Schulten et al. [15, 16]. 

Linden HB. Liquid injection field desorption ionization a new tool for soft ionization of samples including air-sensitive catalysts and non-polar hydrocarbons. Fur. J Mass Spectrom. 

Smith DF, Schaub TM, Rodgers RP, Hendrickson CL, Marshall AG. Automated liquid injection field desorption/ionization for Fourier transform ion cyclotron resonance mass spectrometry. Anal Chem. 2008 80 7379-82. 

Gross JH. Liquid injection field desorption/ionization-mass spectrometry of ionic liquids. J Am Soc Mass Spectrom. 2007 18 2254-62. 

Liquid chromatography/mass spectrometry Laser-induced dissociation Liquid injection field desorption ionization Linear-acceleration high-pressure collision cell Linear quadntpole ion trap... 

Linden, H.B. Liquid Injection Field Desorption Ionization a New Tool for Soft lortization of Samples Including Air-Sensitive Catalysts and Non-Polar Hydrocarbons. Eur. J. Mass Spectrom. 2004,70,459-468. 

Smith, D.F. Schaub, T.M. Rodgers, R.P. Hendrickson, C.L. Marshall, A.G. Automated Liquid Injection Field Desorption/Ionization for Fourier Transform Ion Cyclotron Resonance Mass Spectrometry. Anal. Chem. 2008, 80, 7379-7382. 

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