ThermoFisher Scientific Vanquish VC-D50, Operating Manual

Page: 107 / 188

6 • Operation
Fluorescence Detectors (VC-D50, VC-D51, VF-D50, VF-D51)
Operating Manual Page 107
• Observe the general guidelines and recommendations on the use of
solvents and additives in the chromatography system. Refer to
Use
of Solvents and Additives in the Vanquish System Operating Manual .
See also
2 Overview of Optimization Parameters ( } page 107)
2 Monitoring the Lamp Age ( } page 131)
6.9.2 Overview of Optimization Parameters
The following table serves as an overview of parameters that influence
detector performance and indicates the performance characteristics
affected. The sections below offer guidelines for selecting the
parameters.
Parameter Affects
Excitation wavelength,
emission wavelength Fluorescence intensity, limit of detection,
selectivity
Sensitivity Baseline noise, max. fluorescence intensity
Filter wheel setting Baseline noise, permitted wavelength range for
emission
PMT Emission wavelength range (and therefore
excitation wavelength range)
Response time Baseline noise, peak width, peak height
Data collection rate Peak resolution, disk space, possibly baseline noise
Flow cell temperature Fluorescence intensity, reproducibility
Lamp mode Lamp lifetime, baseline noise, maximum data
collection rate
Baseline behavior Course of the baseline after switching the
wavelength, sensitivity, filter wheel, or PMT.
6.9.3 Determining the Optimum Excitation and Emission Wavelength
The most important parameters that need to be optimized are the
excitation and emission wavelength. Note the following key criteria for
determining the wavelength for an analysis:
• Preferably, select an excitation wavelength on the absorption
maximum of the sample components.
• Avoid the wavelength range where the solvents absorb (for
example, below 220 nm for methanol and below 210 nm for
acetonitrile). The excitation wavelength should always be selected