OpenLab CDS allows you to continue using a calibration curve that has been created in EZChrom. Follow the steps below if you cannot acquire calibration standards with OpenLab CDS, or if you want to benefit from the calibration standards acquired with EZChrom.
Use the EZchrom Migration Tool to migrate your EZChrom methods.
This tool aligns the different scales in EZChrom and OpenLab CDS.
Import the migrated EZChrom methods.
Acquire your samples with OpenLab CDS, and process them with the imported method.
The calibration curve is built with the information coming from EZChrom.
Please note the differences in quantitation between EZChrom and OpenLab CDS described below.
Just after the import, the Last calibration date displayed in the method is the date and time of the import. After processing the samples, it is the date and time of the processing.
The import does not differentiate between enabled and disabled calibration points. If you had disabled calibration points in EZChrom, you must disable them again in the imported method.
If the calibration curve is forced through the origin (Origin=Force), OpenLab CDS calculates the uncentered determination coefficient.
If RF definition is set to Response per amount, residuals are calculated differently in EZChrom and OpenLab CDS.
In EZChrom, a residual is the difference between the concentration entered by the user and the concentration read from the calculated calibration curve.
In OpenLab CDS, the residual is the difference between the measured and the predicted response or amount (depending on the curve orientation).
If the RF definition is Amount per Response, residuals will be the same in OpenLab CDS and in EZChrom.
There is no rolling average in OpenLab CDS. If a rolling average with n replicates is configured in the EZchrom method, the average of the last n replicates is imported into OpenLab CDS. In OpenLab CDS, the Curve calculation mode is set to From average per level.
In EZChrom, you can configure a weighted average for a calibration standard. The Calib Weight factor defines to which extend calibration replicates from a previous processing are taken into account. In OpenLab CDS, there is no equivalent setting. The values of the previous processing are not taken into account. Only the average value of all replicates of the last set of calibration standards is imported.
The calculation for timed groups with identified compounds differ if the option Quantify each peak individually is selected.
In EZChrom, identified compounds for which no calibration settings are defined are not quantified.
In OpenLab CDS, identified compounds for which no calibration settings are defined are quantified with the group response factor or calibration curve of the group.
If the method contains compounds with Response scaling set to log(response) or sqrt(response), EZChrom and OpenLab CDS may use different algorithms.
Calculations differ in the scenarios described below: