ThermoFisher Scientific Vanquish VC-D50, Operating Manual, Page: 99 / 188

6 • Operation
Fluorescence Detectors (VC-D50, VC-D51, VF-D50, VF-D51)
Operating Manual Page 99
6.7 Operational Modes of the Detector
The device provides five operational modes:
• Single-channel mode
• Multi-channel mode
• Zero Order Mode
• Single spectrum scan
• FL Field Acquisition
6.7.1 Single-Channel Mode
A fluorescence detector is usually operated in single-channel mode, that
is, a
single excitation/emission wavelength pair is measured over time.
Other wavelength pairs and related detection parameters can be set at
any time of the separation to adapt to the specifics of the analytes.
Preferably this change should take place while no peak is detected. As
this mode provides the highest possible data rates and best signal-to-
noise ratio, always use the single-channel mode for very small peaks.
6.7.2 Multi-Channel Mode (VF detectors only)
In multi-channel mode, both monochromators quickly switch between
the selected wavelengths. A single analysis is sufficient to measure
several channels. The detector can acquire up to four wavelength pairs
simultaneously. However, note that:
• Each additional channel increases the time that the detector
requires to set the grating positions, reduces maximum possible
data collection rate, and leads to an increased baseline noise.
• Switching permanently between the wavelengths can lead to wear
in the long term. The multi-channel mode is therefore only
recommended for method development, but not for continuous
routine operation.
• As an alternative, you can switch the wavelengths as often as
required between different peaks in a single data channel in the
Chromeleon software. In addition to the excitation and emission
wavelength, you can switch the sensitivity, the emission filter, PMT
and lamp mode.