Editing Signal-Dependent Fraction Collection ParametersCollecting Fractions
Editing Signal-Dependent Fraction Collection Parameters
After you have created a basic program with the PGM Wizard, you can later edit this program in the PGM Editor as described in 
Creating and Modifying PGM Files.
Independently of the installed Fraction Collector, the Fraction Collection driver supports several PGM Wizard parameters. These parameters, which are described in the tables below, allow you to start fraction collection in the PGM File (or on the Control Panel).
Press the F8 key to open the Commands dialog box, and then enter the parameters in the PGM Editor. You can also establish controls with the desired functionality on the control panel. (For more information, refer to Controlling Devices from the Control Panel Modifying a Control Panel.)
The tables below list the parameters in the Commands dialog box for the associated DetectionChannel. (For information about the read-only parameters, refer to Checking the Fraction Collection Status on the Control Panel.)
Signal-Based Parameters (Min., Max., and Default depend on the detector; here, they are shown for a UV detector)
|
Parameter |
Min. |
Max. |
Description |
|
BaselineDrift 1 |
-1e10 |
1e10 |
Baseline drift in [Signal]/s used to correct the signal value. The specified thresholds (PeakStartThreshold, PeakEndThreshold, and ThresholdNoPeakEnd) are compared to: Dt is set to 0 whenever BaselineDrift changes. Baseline Offset is then set to the current value of the correction term. Thus, the BaselineDrift value always matches the actual drift. |
|
BaselineOffset 1 |
-1e10 |
1e10 |
Baseline offset in [Signal] used to correct the signal value. |
|
DerivStep |
0.02 s |
60.00 s |
Time for which the signal values are evaluated to determine the signal slope and the curve. |
|
Name |
N/a |
n/a |
Name of the signal channel used for peak detection (this may be a Virtual Signal, also). |
|
OffsetTime |
0.0 s |
9999.9 s |
Retention time offsets between the first detector and other detectors.
Make sure the retention time setting for this command is later than the DelayTime (see below). |
|
OffsetVolume |
0.0 µl |
5000.0 µl |
Offset volume between the first detector and other detectors. (Based on the flow, the offset volume is converted into the corresponding OffsetTime.) |
|
PeakEndCurve* |
0 |
10^10 |
Curve in [Signal]/s^2 that must be exceeded for a shoulder to be recognized after the peak maximum. |
|
PeakEndSlope* 1 |
-1e10 |
0.000 |
The slope value in [Signal]/s must exceed the PeakEndSlope value for the peak end to be recognized. |
|
PeakEndThreshold* 1 |
-1e10 |
1e10 |
The actual signal value in [Signal] must be below the PeakEndThreshold value for the peak end to be recognized. |
|
PeakEndTrueTime* |
0.0 s |
4.0 s |
The time must be fulfilled for the different conditions for a peak end to be recognized. |
|
PeakMaxSlope *1 |
-1e10 |
0 |
The actual slope value in [Singal]/s must be below the PeakMaxSlope value for the peak maximum to be recognized. |
|
PeakMaxTrueTime* |
0.0 s |
4.0 s |
The time must be fulfilled for the different conditions for a peak maximum to be recognized. |
|
PeakStartCurve* |
0 |
10^10 |
Curve in [Signal]/s^2 that must be exceeded for a shoulder to be recognized after the peak start. |
|
PeakStartSlope*1 |
0.000 |
1e10 |
The actual slope value in [Signal]/s must exceed the PeakStartSlope value for the peak start to be recognized. |
|
PeakStartThreshold * ² |
-1e10 |
1e10 |
The actual signal value in [Signal]/s must exceed the PeakStartThreshold value for the peak start to be recognized. |
|
PeakStartTrueTime* |
0.0 s |
4.0 s |
The time must be fulfilled for the different conditions for a peak start to be recognized. |
|
ThresholdDoNot |
-10^10 |
10^10 |
Threshold value for the slope in [Signal]/s above which peak detection via the PeakEndSlope parameter is disabled. Instead, a new peak is detected and a tube change is triggered when the signal slope is 0.0. |
|
ThresholdNoPeak |
-1e10 |
1e10 |
The actual signal threshold value in [Signal] must be below the ThresholdNoPeakEnd value for the peak end to be recognized. (This parameter supports the PeakEndSlope parameter for peak detection.) |
Tips:
*To ignore the parameter for peak detection, set the parameter to Off.
1Set these parameters on the Peak Detection Options page in the PGM Wizard.
Commands
In addition, you can enter the following commands manually for a specified retention time:
|
Command |
Description |
|
ManualPeakEnd |
Stops the current peak at the specified retention time, independently of the peak detection parameters. |
|
ManualPeakStart |
Starts the next peak at the specified retention time, independently of the peak detection parameters. |
|
ManualTubeChange |
Changes to the next tube at the specified retention time, independently of the peak detection parameters. |
For the signal-independent parameters, refer to Editing Signal-Independent Fraction Collection Parameters.
For an overview of the fraction collection topics, refer to Collecting Fractions.