Agilent 1290 Infinity LC System Manual and Quick Reference
65
Optimization of the Agilent 1290 Infinity LC System
3
How to Achieve Higher Sensitivity
The
peak width
setting in the detector allows the user to correctly set these
parameters without needing any knowledge other than sight of the
chromatogram integration results to see how wide the peaks are. The peak
width setting should be set for the narrowest peak width observed in the
chromatogram. If it is set too wide it will make the peaks appear lower in
height and wider (and potentially less resolved) and if it is set too narrow it
will increase the baseline noise unnecessarily. Essentially the software uses
this value to set the
data collection rate
such that it collects enough data
points over the narrowest peaks and it is aiming for 15 to 25 points across a
peak. The 1290 Infinity DAD can collect at a maximum 160 Hz if required
which would allow enough data points to be collected over a peak that is only
0.1 s wide. The
response time
setting is another way of indicating how this
filtering is set. It is measured in seconds and is about one-third of the peak
width value (which is measured in minutes). It effectively shows how quickly
the plotted signal responds to a step change in the input signal.
Table 8
Peak Width — Response Time — Data Rate
Peak width at half height [min]
1
1
Values in the User Interface may be rounded.
Response [s]
Data rate [Hz]
< 0.0015625
0.015625
160
> 0.0015625
0.03125
160
> 0.003125
0.0625
80
> 0.00625
0.125
40
> 0.0125
0.25
20
> 0.025
0.5
10
> 0.05
1.0
5
> 0.1
2.0
2.5
> 0.2
4.0
1.25
> 0.4
8.0
0.625
> 0.85
16.0
0.3125
