Thermo Scientific Thermo Scientific Vanquish VC-D40, Operating Manual

Page: 91 / 174

6 • Operation
Variable Wavelength Detectors (VC-D40, VF-D40)
Operating Manual Page 91
6.8.2 Overview of Optimization Parameters
The following table serves as an overview of parameters that influence
the detector performance and indicates the performance characteristics
affected.
Parameter Affects
Wavelength Sensitivity, linearity
Data collection rate Peak resolution, disk space
Response Time/Peak width Baseline noise, peak width, chromatographic
resolution, sensitivity
Baseline behavior Behavior of the baseline after switching the
wavelength
For further information about the parameters, refer to the Chromeleon
Help .
6.8.3 Wavelength
The most important parameter that needs to be optimized is the
wavelength. Note the following key criteria for determining the
wavelength for an analysis:
• Preferably, select a wavelength on the absorption maximum of the
sample components.
• Avoid the wavelength range where the solvents absorb strongly (for
example, below 220 nm for methanol and below 210 nm for
acetonitrile). The wavelength should always be selected above the
UV cutoff of the solvent. For information about the UV cutoff
wavelengths of solvents, see
UV Cutoff Wavelengths of Solvents
( } page 165) .
Wavelength switching in the Chromeleon software
Thermo Fisher Scientific recommends using the single-channel mode to
record data by switching the wavelengths in-between the detected
peaks of the various sample components, rather than to simultaneously
measure all wavelengths in multi-channel mode.
Use the Instrument Method Wizard to set the start wavelength for one
channel. After completion of the wizard, open the method in the
Instrument Method Editor. In the Module View for the detector, on the
Timetable tab page, you can define the times for switching the
wavelengths and other parameters.