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.
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.