Agilent Technologies 1100 Series Reference Manual page 30

2
First Steps with the Fluorescence Detector
4 Evaluating fluorescence spectra
5 Switching lamp on only for analysis
For highest reproducibility and linearity change the lamp setting to always ON (default is on
NO TE
only during run).
One hour of initial warm-up of the instrument is recommended.
6 Do not overpressurize the detector quartz flow cell
When comparing fluorescence excitation spectra directly with DAD spectra or literature
NO TE
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.
32
In contrast to diode array based UV detectors where UV spectra are
evaluated by taking a spectrum at the peak maximum and selecting a
reference spectrum at the baseline, correct fluorescence spectra are
obtained by selecting a peak maximum spectrum and a reference around
the inflection points. Selecting reference spectra at the baseline is not
useful because the spectrum on the baseline is very noisy (no light!).
Unless maximum sensitivity is needed, the lamp lifetime can significantly
be increased by switching it on just for analysis. In contrast to other LC
detectors the G1321A fluorescence detector equilibrates within seconds
after the lamp is switched on.
Be aware to not exceed a 20 bar pressure drop after the flow cell when
hooking up additional devices like other detectors or a fraction collector.
It's better to place a UV detector before the G1321A fluorescence detector.
1100 Series FD Reference Manual