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thermospray is similar to that of the particle beam interface which will also be described later.

The properties of the thermospray system were investigated by Voyksner et al. [13]. They noted that the
LC/MS thermal spray system frequently produced molecular weight information (parent ions), and
exhibited lower detection limits than the other forms of LC/MS interfaces.

Figure 9.17
The Thermospray LC/MS Interface
They found that when they used a thermal spray system with a 0.1 M ammonia acetate buffer, and a
mobile phase that contained a high proportion of water, high sensitivities were achieved. The optimum
interface temperature varied with solvent composition and could be determined by maximizing the
solvent buffer ion intensities. The spectra obtained from thermospray ionization resembles chemical
ionization using ammonia as the chemical ionization reagent. The ions formed appear to be the result of
protenation, resulting in ammonium addition and proton-bound solvent molecular clusters. The
thermospray ionizing procedure