Undesirable effects
5-7
Normalized absorbance spectra of a compound at two concentrations
Undesirable effects
Shape differences between absorbance spectra can be caused by one or more of
the following undesirable effects:
•
Detector noise
•
Photometric error caused by high sample concentration
•
Variation in solvent composition
These sources of spectral variation can cause chemically pure,
baseline-resolved peaks to exhibit a small level of spectral inhomogeneity. You
can assess the significance of spectral inhomogeneity by comparing a spectral
contrast angle to a threshold angle (see
page 5-8
).
Normalized spectra of a compound at different
concentrations
Spectral contrast angle: 3.4
°
Wavelength (nm)
Region of little or no
analyte absorption
No
rmal
ized ab
sorban
ce
Summary of Contents for 2998
Page 12: ...xii Table of Contents...
Page 26: ...1 14 2998 PDA Detector Optics Principles...
Page 62: ...3 12 Maintaining the Detector...
Page 82: ...5 10 Spectral Contrast Theory...
Page 96: ...A 14 Safety Advisories...
