Time-of-Flight Section

Like the magnetic sector, the TOP section by itself is not capable of MS/MS operation, but allied with the sector, the two make an excellent MS/MS instrument. 

The AutoSpec -TOF hybrid mass spectrometer combines the advantages of a magnetic/electric-sector instrument with those of time-of-flight to give a versatile instrument capable of MS or MS/MS at high or low resolution. 

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), plas-maspray, thermospray, atmospheric-pressure chemical ionization (APCI), and electrospray (ES) 

Ion formation region from suitable atmospheric pressure inlet 

Optional additional detection device before entry to mass spectrometer proper 

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Electron Drift in a Constant Electric Field. As an example, let us consider the system discussed in the time-of-flight section. In this system, charge carriers are generated close to the injecting contact and drift to the collecting contact under the force of a constant electric field. As discussed above, the current response on a laser pulse has a constant value of Jph = AQIr for 0 < t < t, and drops instantly to zero at t=r. The input signal is a delta function and the output response is a step function. Linear-response theory shows that the system function H s) is the Laplace transform of the impulse response function h(t). In our example ... 

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