Resolving Spectral Data - Waters ACQUITY UPLC Operator's, Overview And Maintenance Manual

Resolving spectral data

Together with photodiode spacing, the detector's 100-µm-wide slit
(50-µm-wide slit for eλPDA) determines the intensity and bandwidth of the
light that strikes the photodiode array. Variations in intensity and bandwidth
provide the means to distinguish among similar spectra.
The grating images the slit onto the photodiode array. The angle of diffraction
from the grating determines the wavelength that strikes a particular
photodiode in the array.
The following figure shows an absorbance spectrum of benzene. Note that the
wavelength resolution is sufficient to resolve five principal absorption peaks.
Benzene spectrum at 1.2 nm resolution
8
nm