Biotage Isolera Four, User Manual

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411829-L, Collection and Fractionation April 2012 Page A-3
A
It is possible to combine the Collect All with the Threshold and/or the Slope collection method. This
means that everything will be collected and fractionation will occur on the Start Threshold level
and/or the Start Slope setting. Fractionation will also occur on detected valleys as well as on
shoulders, if enabled.
Note that the Slope collection mode is not available with the λ -all detection mode or with an external
detector.
A.1.5 Collection and Fractionation Parameters
Method Parameters
The method parameters are defined for each method and can be changed by the user. The following
method parameters are available:
Table A-2: Method Parameters
Parameter Description
Detection Mode The basic configuration for collection and fractionation. The range is [UV1 |
UV1+UV2 |
λ -all | Manual | External]. The λ -all detection mode is only available
on systems with a Spektra license installed.
Baseline Correction Used to remove the interference of the light absorbance of the used solvents from
the absorbance signal during the chromatography. (Only available on systems
with a Spektra license installed.)
If this option is turned on, the gradient run is preceded by a short solvent light
absorbance detection phase. During this phase, the light absorbance of the used
solvents is measured at all wavelengths that will be used for collection and
fractionation (UV1, UV1+UV2, or
λ -all). The measurement results in a baseline
containing the maximum absorbance of the solvent system at each wavelength
used, a solvent absorbance spectrum. During the gradient run, the maximum
solvent absorbance spectrum is subtracted from the signal presented by the
detector. Only absorbance values above zero are reported, anything below that is
reported as zero. In effect this automates the procedure of manually excluding
parts of the spectrum from the summation. In a normal use case, peaks that have
absorbance overlapping that of the solvent are detected because of absorbance
outside of the excluded range.
Start Wavelength The shortest wavelength to be included in the λ -all signal. The range is 200 to 400
nm (dual variable UV detector) or 200 to 800 nm (UV-VIS detector). (Only
available with the
λ -all detection mode.)
End Wavelength The longest wavelength to be included in the λ -all signal. The range is 200 to 400
nm (dual variable UV detector) or 200 to 800 nm (UV-VIS detector). (Only
available with the
λ -all detection mode.)
Collect All Used to collect the entire run. The range is [On | Off].
Start Threshold Used to collect samples with a light absorbance exceeding the set absorbance
threshold. The range is [Off | 0 to 6000 mAU].
Initial Waste Delay collection until a specified volume has been delivered to the waste.
The range is [0 to 10000 ml]. If the gradient is defined in CV, then the initial waste
is also defined in CV.
Slope Mode Used to collect samples based on the start slope of light peaks. The range is [Off |
Low Slope | Medium Slope | Custom Slope]. (Only available with the UV1 and
UV1+UV2 detection modes.)