Calibration Options
Tabs: Calibration Options - Defaults
The Calibration Options dialog contains various settings that influence calibration. It can be opened via the Calibration - Options... menu item or by clicking the 
icon. The settings configured here are stored in the calibration file.
Calibration Options - Calibration Options
Contains a brief description of the calibration file. When a calibration file is loaded, this text is displayed in the Description field of the Open dialog; it is also shown in the Description field of the Method Setup - Calculation tab when a calibration is loaded there.
Sets the method of the calibration curve display (suitable for different types of calibration curve use):
Caution:
This parameter only indicates the display method. The actual type of calculation upon evaluation of unknown compounds can be selected in the Chromatogram window in the Result tab using the Calculation parameter.
Displays the dependence of a compound’s response to its quantity.
Relative calibration curve:
- If the amount of the internal standard has not been entered, displays the dependence of compound/internal standard response ratio to amount of compound.
- If the amount of the internal standard has been entered, displays the dependence of compound/internal standard response ratio to the compound/internal standard amount ratio.
Displays the dependence of a compound's response to its quantity, just like for the ESTD type, but with added checks on calibration and chromatogram validity. Namely, the chromatogram must have empty Sample Amount value and all peaks found in the chromatogram must have Amounts calculated, either through the calibration or through Unidentified Peak Response parameter.
Displays the dependence of a compound's response to its quantity, but the graph is shifted so that the calibration curve crosses the x-axis.
Selects the number of displayed signals when a multi-detector calibration is used. The default value is 1. The change is manifested in the number of commands in the Calibration - Set Signal menu and in the number of colored squares on the Overlay toolbar. If a calibration standard chromatogram is opened, the Number of Signals matches the number of signals from the calibration standard chromatogram and cannot be changed, so the field is disabled.
Sets the calibration or recalibration method for the Add All, Add Peak and Add Group commands. It can be also changed in the toolbar of the Calibration window. Possible options are:
Automatically transfers all data related to compounds from a chromatogram to the calibration file. The data can be modified and supplemented later on.
Enables to enter the amount of the component or to modify or add the remaining data for each compound by opening one of the Manual Calibration and Recalibration or (Re)Calibrate Group dialogs.
Determines how the calibration process is performed. This setting applies only when working manually in the Calibration window. When calibration is performed from Single Analysis or Sequence, the specified calibration level is always recalibrated according to the settings in Recalibration options. It can be also changed in the toolbar of the Calibration window. For Standard Addition calibrations, this selection is disabled.
Calibrate
Transfers data from the standard chromatogram into the first available empty calibration level. If all 20 calibration levels are filled, the responses in the last (Blank) calibration level will be overwritten.
Recalibrate
Recalibrates the level currently selected in the calibration window with the data from the standard chromatogram.
Enables verification of the calibration curve’s linearity based on two following parameters. If either parameter fails for a given compound, the entire Curve Check for that compound is considered failed. This is indicated in the Calibration window on the compound’s tab and reflected in the Result Table of the Chromatogram window, where the Peak Type column will display Error (Curve Check).
Sets the value for the maximal allowed standard deviation of each point in the calibration curve of the given compound.
Sets the value for the minimal allowed correlation factor as calculated on the tab of the individual compound.
Specifies where the (re)calibration will be performed. This setting can also be changed in the toolbar of the Calibration window.
On All Signals
Calibration or recalibration is performed on all signals. When Add All is clicked, all peaks from the currently active signal are added to the Calibration Summary Table. For subsequent signals, responses for these peaks are filled in if they are found. However, any additional peaks present in these signals are not added automatically - they must be added separately by switching to the respective signal and using Add All or other functions again.
All added peaks have the Used checkbox checked on all signals. This option is selected by default when creating a new calibration.
On Active Signal
Calibration or recalibration is performed only on the currently active signal. When Add All is clicked, all peaks from the active signal are added to the Calibration Summary Table. The responses for these peaks are filled in only for the active signal, even if they are found on other signals. On all other signals, the Used checkbox for these peaks is unchecked. In this mode automatically created compound name is amended by signal name to the form "Peak [retention time] [signal name]".
Defines the conditions for recalibration mode:
Each new response replaces the previous one, ensuring that only one response of each compound is stored for each calibration level.
The average response value is calculated as the arithmetic mean of the responses from the last X recalibrations for the given level, where X is defined by the No. of Points setting.
Specifies how many last recalibrations are used for averaging. The No. of Points can be set between 0 and 100, with a default value of 10.
Note:
Changing the No. of Points setting does not retroactively affect existing recalibrations - it only applies to future recalibrations.
Specifies the units for compound quantities. Units are stated for all displayed amounts in calibration tables and graphs as well as in the Result Table in the Chromatogram window, unless other units are specified by Scale Factor and Units after Scaling fields.
Specifies the maximum allowed percent deviation of response for recalibration. The allowed deviation range is 1 to 50%.
When Calibration option is set to Automatic
If the deviation in the response exceeds the set threshold, recalibration is not performed, and the event is logged in the audit trail.
When Calibration is set to Manual
If the deviation in the response exceeds the set threshold, the Over is stated in the dialog for manual recalibration. After confirmation, recalibration is still performed.
Enable Manual Response Value Change
Enables the manual modification of responses (in the Response or Area and Height fields).
Enables the automatic update of retention time after each (re)calibration. The retention time of the compound is adjusted to the current value of the peak identified as that compound.
Corrects response values for differences in injected volume by comparing the actual injection (from the Inj. Volume in the chromatogram) with the Default Injected Volume. The response is adjusted based on their ratio, assuming a direct proportionality between amount and response.
When the Inj. Volume in the standard chromatogram is set to the actual injected amount, and the Default Injected Volume is defined in calibration before (re)calibrating, the response for each level in calibration is corrected accordingly. This ensures that the calibration reflects response values as if the default volume had been used. The corrected response is recorded in Calibration Point Details in the format: Corrected by Injection Volume (Default X ml, Actual X ml).
Changing the Default Injected Volume setting does not retroactively affect previous (re)calibrations. The response values in the calibration table remain unchanged, only the values in the evaluated chromatogram in the Chromatogram window are corrected.
Retention Indexes use Log. Interpolation with Unretained Peak
Uses Unretained Time value (set on the Method Setup - Advanced tab) for retention index calculation. By default, this checkbox is unchecked and retention indexes are calculated using the linear interpolation. When it is checked, then the logarithmic interpolation with unretained peak time is used instead.
Equation used for the linear calculation of the Retention Indexes:
Where:
- I = Kováts retention index,
- n = the number of carbon atoms in the smaller n-alkane,
- N = the number of carbon atoms in the larger n-alkane,
- z = the difference of the number of carbon atoms in the smaller and larger alkane,
- tr = the retention time.
Equation used for the logarithmic calculation of the Retention Indexes:
Where:
- I = Kováts retention index,
- n = the number of carbon atoms in the smaller n-alkane,
- N = the number of carbon atoms in the larger n-alkane,
- tr' = the adjusted retention time (tr'=tr-t0').
Response Factor as Response / Amount
Enables calculating Response Factor as RF = Response / Amount (by default : RF = Amount / Response). This setting changes the format of RF in Calibration window as well as on Results tab of the Chromatogram window.