Agilent Technologies 1100 Series Reference Manual page 32

2 How to optmize the Detector
2 Connection of flow cell
•
For flow rates from 0.5 ml/min connect column using the zero-
dead-volume fittings of the detector.
•
For small column i.d. (e.g 1 mm) the inlet capillary of the micro
flow cell can be connected directly to the column.
3 Setting the peak width (response time)
•
Use peak width according
•
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 bandwidth if you need
selectivity, e.g. 250,10 nm and 360,100 nm as reference
wavelength.
•
Set the sample wavelength to a peak or valley in the spectrum to
get best linearity for high concentrations.
•
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).
Table 4 Optimization Overview, continued
Parameter
5 Setting the slit width
•
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. 16 nm) to detect very low concentrations.
•
Optimizing spectral acquisition (DAD only)
•
Select spectra acquisition mode according to your needs (see
Optio s fo sto i g spe t a
•
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 resolution of spectra with fine structure is wanted.
Typical column Typical peak
length width
T<= 5 cm 0.025 min
32 1100 Series DAD and MWD Reference Manual
Figure 7 as starting point.
•
on page 42).
Recommended flow cell
•
chromatographic resolution
• peak resolution versus sensitivity versus
disk space
• sensitivity versus selectivity
• sensitivity versus linearity
• baseline drift due to RI effects.
Impact
spectral resolution, sensitivity and
linearity.
High pressure
flow cell for