Agilent InfinityLab LC Series Diode Array Detectors User Manual
77
5
Optimizing the Detector
Optimization Overview
Optimization Overview
Table 15
Optimization Overview
Parameter
Impact
1
Selection of flow cell
•
peak resolution versus sensitivity
•
Choose flow cell according to used column (
page 78).
2
Connection of flow cell
•
chromatographic resolution
3
Setting the peak width (response time)
•
peak resolution versus sensitivity ver
-
sus disk space
•
on page 78 as starting
point.
•
Set the peak-width close to the width of a narrow peak of interest in your
chromatogram.
4
Setting wavelength and bandwidth
•
Sample wavelength:
•
Never miss a peak by the use of a browser wavelength like 250 nm with
100 nm bandwidth.
•
Select specific wavelength with reduced optical bandwidth if you need
selectivity, e.g. 254.0 nm / 4 nm and 360.0 nm / 100 nm as reference
wavelength.
•
Set the sample wavelength to a peak or valley to get best linearity in
general; select a valley to get best linearity for high concentrations.
•
sensitivity versus selectivity
•
sensitivity versus linearity
•
Reference wavelength:
•
Select the reference wavelength with broad bandwidth (30...100 nm)
wavelength range where your analytes have little or no absorbance (e.g.
sample at 254 nm, reference at 320 nm).
•
Select the reference wavelength as near as possible to the UV range.
•
baseline drift due to RI effects.
5
Setting the slit width (G7117B only)
•
Use 4 nm slit for normal applications.
•
Use narrow slit (e.g 1 nm) if your analytes have narrow absorbance bands
and for high concentrations.
•
Use a wide slit (e.g. 8 nm) to detect very low concentrations.
•
Optimizing spectral acquisition (DAD only)
•
Set the spectral wavelength range (for colorless samples 190...400 nm is
sufficient).
•
Set step to 4 nm for normal use; set small step (and slit width) if high resolu
-
tion of spectra with fine structure is wanted.
•
spectral resolution, sensitivity and lin
-
earity.
