ABSTRACT

The LC/TOF instrument was designed specifically for use with the effluent flowing from LC columns, but it can be used also with static solutions. The initial problem with either of these inlets revolves around how to remove the solvent without affecting the substrate (solute) dissolved in it. Without this step, upon ionization, the large excess of ionized solvent molecules would make it difficult if not impossible to observe ions due only to the substrate. Combined inlet/ionization systems are ideal for this purpose. For example, dynamic fast-atom bombardment (FAB), plasmaspray, thermospray, atmospheric-pressure chemical ionization (APCI), and electrospray (ES)

have all been used, but only the last two are now common. The ES inlet has evolved into the highly efficient Z-spray (see Chapter 10, “Z-Spray Combined Inlet/Ionization Source”). After passing through such inlets, most of the solvent is removed.