Particle beam interface for LC-MS

Particle beam interfaces use jet separators and differential pumping to separate solvent from the solute before the ionisation step. Once separated from the solvent the sample is ionised using conventional EI/CI sources. The resulting spectra are therefore compatible with library spectra obtained with conventional El systems. 

Particle beam (PB) El MS is less sensitive than capillary GC-MS. This can be partly compensated for by the fact that much larger volumes of sample can be introduced in the LC-MS method [8]. The method can therefore be applied to the trace analysis of nonionic surfactants. Certain species, which due to their low volatility, high polarity or thermal instability cannot be detected by GC-MS, can be analysed by LC-PB-MS. Similarly, some highly volatile species are difficult to analyse by PB-MS, and the two techniques are therefore complementary. 

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Mass spectrometer (MS) [S] sales have always been high, especially since MS is the principal detector in a number of hyphenated techniques such as GC-MS, MS-MS, and LC-MS. The GC — MS combination accounts for about 60% of MS sales since it is used widely in drug and environmental testing. Innovations in interface technology such as inductively coupled plasma (ICP)-MS, FC-MS and thermospray or particle beam interfaces for LC-MS have both advanced the technology and expanded the interest in applications. Recent introductions of lower cost MS instruments with automated sampling and computerized data analysis have added to the attraction of the technique for first-time users. 

Figure 5.7. Particle-beam interface for LC/MS coupling. (Reproduced from ref. 6 by permission of WUey-lnterscience, copyright 1997.)...

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