Agilent Technologies 1100 Series Reference Manual page 50

2 First Steps with the Fluorescence Detector
Multi wavelength detection
Time-programmed wavelength switching traditionally is used to achieve low limits of
detection and high selectivity in routine quantitative analysis. Such switching is
difficult
if compounds elute closely and require a change in excitation or emission wavelength.
Peaks can be distorted and quantitation made impossible if wavelength switching occurs
during the elution of a compound. Very often this happens with complex matrices,
influencing the retention of compounds.
In spectral mode, the Agilent 1100 Series FLD can acquire up to four different signals
simultaneously. All of them can be used for quantitative analysis. Apart from complex
matrices, this is advantageous when watching for impurities at additional wavelengths.
It is also advantageous for reaching low limits of detection or increasing selectivity
through optimum wavelength settings at any time. The number of data points acquired
per signal is reduced and thus limits of detection may be higher, depending on the
detector settings compared to the signal mode.
PNA analysis, for example, can be performed with simultaneous multi wavelength
detection instead of wavelength-switching. With four different wavelengths for
emission, all 15 PNAs can be monitored
Table 10
Column
Mobile phase
Gradient
Flow rate
Column temperature
Injection volume
FLD settings
50 1100 Series FD Reference Manual
Conditions for Figure 17
(Figure 17 on page 53).
on page 53
Vydac, 2.1 x 250 mm, PNA, 5 µm
A = water; B = acetonitrile (50:50)
3 minutes, 60%
14.5 minutes, 90%
22.5 minutes, 95%
0.4 ml/min
°
22 C
2 µl
PMT 12,
response time 4
s,