Thermo Scientific Thermo Scientific Vanquish VC-D40, Operating Manual

Page: 165 / 174

11 • Appendix
Variable Wavelength Detectors (VC-D40, VF-D40)
Operating Manual Page 165
11.2 UV Cutoff Wavelengths of Solvents
The UV cutoff wavelength is the minimum effective wavelength for the
measurement. The mobile phase composition affects its UV cutoff
wavelength.
In general, mobile phases are solvents, such as, water, acetonitrile,
methanol, or other substances. They may also contain salts, such as
sodium hydroxide (NaOH).
Most solvents have a UV cutoff wavelength within the spectral range of
the device. For optimum measurement results, perform quantitative
measurements at a wavelength that is sufficiently above the UV cutoff
wavelength. The UV cutoff wavelength also depends on the quality of
the solvent. For information about the UV cutoff wavelength for a
solvent, contact the manufacturer of the solvent.
The refractive index of different solvents can differ. Therefore, changing
the mobile phase composition can lead to baseline fluctuations.