Agilent Technologies 1100 Series Reference Manual page 44

2
First Steps with the Fluorescence Detector
Procedure III - Make a single run with the Agilent 1100 Series DAD/FLD
combination
For most organic compounds, UV-spectra from diode array detectors are
nearly identical to fluorescence excitation spectra. Spectral differences are
caused by specific detector characteristics such as spectral resolution or light
sources.
In practice, combining a diode array detector with a fluorescence detector in
series gives the full data set needed to achieve the optimum fluorescence
excitation and emission wavelengths for a series of compounds in a single run.
With the UV/Visible/excitation spectra available from the diode array detector,
the fluorescence detector is set to acquire emission spectra with a fixed
excitation wavelength in the low UV range.
The example is taken from the quality control of carbamates. Samples are
analyzed for the impurities 2,3-diamino-phenazine (DAP) and
2-amino-3-hydroxyphenazine (AHP). Reference samples of DAP and AHP were
analyzed with diode array and fluorescence detection. Figure 9 shows the
spectra obtained from both detectors for DAP. The excitation spectrum of DAP
is very similar to the UV absorption spectrum from the diode array detector.
Figure 16 on page 47 shows the successful application of the method to a
carbamate sample and a pure mixture of DAP and AHP for reference. The
column was overloaded with the non-fluorescent carbamate (2-benzimidazole
carbamic acid methylester/MBC) to see the known impurities, AHP and DAP.
46 1100 Series FD Reference Manual