This Information Applies To: OpenLab CDS (ver 2.x)
In the following procedure, you will find steps to create a multipoint ESTD calibration method with OpenLab CDS 2.X.
Steps to follow:
1. Load the Data
a. From Data Selection view > load Data or from Data Processing interface > Open Data. When the window "Create New Processing Method" pops up, choose a method configuration with Calibration feature based on your application (it will not popup if the data has linked method). In this example, we choose GC/LC Quantitative, as shown in Figure 1.
The above step has loaded data and linked them with the default method. If you want to rename the method or create a method for the loaded data, please see the next step b.
b. Go to “Processing” tab in the Data Processing view, and click “New Method”. When “Create New Processing Method” pops out, select “GC/LC Quantitative” (or another method configuration with the Calibration feature) and click “Create method”. This default method cannot be overwritten, so click "Save Method" > " Save Method As" and save it with a unique name.
Select all injections (select the first injection, then hold “Shift” key and click the last injection) and click the method saved in the previous step, then right-click and select "Link selected injections to selected method."
1. Select all injections
2. Click and choose the method
3. Select "Link selected injections to selected method"
Data and Method link should look like this:
1. Chain symbol is shown in front of data
2. Sequence symbol is shown on the right side of method
2. Edit processing method
Optimize the data integration, it is decisive for the quantitative result accuracy.
a. Switch to "Home" tab, click the "Processing Method" button to bring in the "Processing Method" window.
b. Choose the lowest concentration calibration sample data. Set the desired integration parameters according to the chromatogram.
In this example, we do not want to quantify the small peak around 8 minutes. In the integration table, “Slope sensitivity” is changed to 2, “Area reject” value changed to 15 (according to the area of the peak we do not want to quantitate). Add “Integration” “Off” at 0 minutes. Add “Integration” “On” at 2.5 minutes. The later action turns off the integration from 0 to 2.5 minutes. Then add another “Integration” “off” at 9.5 minutes to turn off integration after 9.5 minutes.
c. Bring in the “Peak Details” window in the Home tab and check if integration is correct for all injections, if the integration needs optimization, see the previous step to modify integration parameters again.
d. Click “Reprocess All”, your result should look like this:
e. Focus on lowest concentration calibration sample data. In the Chromatograms window, click the first hollow triangle on top of the peak (it’ll turn to a filled triangle). Hold “Shift” key and click the triangle on top of the last peak to select all the integrated peaks in chromatogram. Right-click any of the selected peaks and select “Add multiple peaks as compounds to method” in the context menu.
1. Click the first peak's hollow triangle on top
2. Hold "shift" key and click the last peak's hollow triangle on top
3. Right-click any of the selected peaks and Select "Add multiple peaks as compounds to method" in the context menu
f. Go to Processing Method > Compounds > Identification > Compound Table, give each added compound a name. Keep the default values of all the other parameters in this table.
g. Go to “Processing Method > Compounds > Calibration > Compound Table, enter the desired values for each column: Amount Unit, Concentration Unit, Response, Mode, Origin, Multiplier (if required), and the concentration for each compound per level. You can use “Fill Down” to quickly fill the columns if the values are the same for that column. In this example, we are going to create a 3-level calibration curve and each level has two parallel injections.
h. On the “General” tab, change “Curve calculation” to “From individual calibration points” (choose the proper Curve Calculation mode based on your application), and set the number of levels for the calibration curve (3 in this example).
i. Select the report template in the Reports > Injection Report, then save the Processing Method.
3. Check and edit injection list:
Bring in “Injection List” from the "Windows" section on ribbon bar (you should be on “Home” tab). Set sample type and levels in Level Column; choose the Run type "Clear all calibration" in the first calibration line (to clear all history points at all levels, and avoid averaging the old curve result with the new one). Enter Multipliers, Dilutions that apply to your analysis. In this example, enter the below values from Sample 1 to 4 in “Multiplier” and “Dil. factor” columns.
1. Injection list tab
2. Set sample type
3. Set levels
4. Select Run type for the first calibration line
4. Reprocess data
Click “Reprocess All”, it will update calibration information and process the sample data in the injection list. Bring in “Calibration curve” window, your calibration curve should look like the following picture:
Navigate to one of the sample injections, bring in “Injection Results” window, you should get the results as shown in Figure 16. Save the results.
Detailed explanation for Curve calculation mode in Processing method > Compounds > Calibration > General
From average per level: Amounts and responses of all calibration points contributing to a level will be averaged and used in the algorithm to calculate the best calibration curve.
From individual calibration points: All amounts and responses of the individual calibration points will be used directly to determine the calibration curve.