User guide

Basic Acquisition Methods
System User Guide
D5033331 A
AB SCIEX TripleTOF
®
5600/5600+ Instruments
45 of 116
Product Ion Mass Spectrometry
In a product ion scan (Product Ion), the system generates mass spectrometric information by
selecting a particular precursor ion window in Q1, fragmenting in Q2 (a collision cell) and pulsing
the ions (fragment ions) into a flight tube and recording their precise arrival time at the detector.
Product ions can provide information on the molecular structure of the original (precursor) ions.
Precursor Ion Mass Spectrometry
In a precursor ion scan, the system detects precursor ions that generate a specific product ion.
The instrument uses Q1 in mass resolving mode to scan over the mass range of interest, while
the TOF section records product ion spectra for each precursor ion. The Q1 mass spectrum
shows all precursor ions that produce the product ion of interest.
About Spectral Data Acquisition
Spectral data can be acquired in one of the following modes, as shown in Table 4-1. Spectral
Data can only be acquired from Q1 and Precursor Ion scan types.
About Instrument Parameters
The working parameters are the set of instrument parameters currently being used.
• Ion Source-dependent (Source and gas) parameters: These parameters can
change depending on the ion source used.
• Compound-dependent parameters: These parameters consist mostly of voltages
in the ion path. Optimal values for compound-dependent parameters vary depending
on the compound being analyzed.
• Detector parameters: These parameters affect the detector. The Multi-Channel
Plate is the detector in a TOF instrument and consists of four channels for ion
detection. The total of the channels equals the ion intensity. This parameter can be
optimized using Instrument Optimization.
The following figure shows the location of the parameters on the ion optics path.
Table 4-1 Spectral Data Acquisition
Mode Description
Profile The preset value is 0.1 Da. Profile data is the data generated by the
instrument and corresponds to the intensity recorded at a series of
evenly spaced discrete mass values. For example, for the mass range
100 Da to 200 Da and step size 0.1, the instrument scans from 100 Da
to 200 Da in 0.1 Da increments (e.g. 100.0, 100.1, 100.2, 100.3… up
to 200.0).
Peak Hopping The preset value is 1.0 Da. Peak Hopping is a mode of operating a
mass spectrometer in which large steps (approximately 1 Da) are
made. It has the advantage of speed (less data steps are made) but
with the loss of peak shape information.