Agilent Technologies 1100 Series, Reference Manual, Page: 63 / 346

Optimizing the Fluorescence Detector
3
1100 Series FD Reference Manual 65
A Real Example
Although an excitation wavelength of 340 nm is quoted in the literature the
Agilent 1100 fluorescence detector scan of orthophthalaldehyde, a derivative
of the amino acid alanine, (
Figure 26 on page 65) shows a maximum between
220 nm and 240 nm.
When you are looking for the wavelength by scanning, scan over the whole
range. As this example shows a maximum may be found in a completely
different wavelength range.
Figure 26 Scan Orthophthalaldehyde Derivative of Alanine
N O T E
When comparing fluorescence excitation spectra directly with DAD spectra or literature
based absorbance spectra, you should consider large differences in the used optical
bandwidth (FLD=20 nm) which cause a systematic wavelength maximum shift depending
on the absorbance spectrum of the compound under evaluation.