How to recalibrate a level in the calibration in Clarity Chromatography Software

Calibration is a critical component of quantitative chromatographic analysis. Accurate calibration curves ensure reliable concentration determinations, compliance with laboratory quality standards, and reproducibility across analytical runs.

This guide provides a detailed explanation of how to correct an individual calibration level in Clarity Chromatography Software, based on the procedures demonstrated in the referenced instructional video.

Whether a calibration point deviates unexpectedly or a standard solution must be remeasured, the software provides two systematic approaches for restoring the accuracy of the calibration curve.

1. Understanding Calibration Level Issues

During routine calibration verification, analysts may observe that one calibration level does not match expected detector response values. This may occur due to:

• Preparation errors in the standard solution
• Instrument instability during injection
• Incorrect injection volume
• Contamination or carryover
• Drift or instrument-related variability

In the example shown in the video, Calibration Level 2 shows values outside the expected trend and requires correction.

Clarity offers two possible remedies:

1. Remove the problematic point from the calibration curve
2. Recalibrate the level by re-running the standard

2. Method 1: Removing a Calibration Point

When to Use This Method

• When the specific standard solution is no longer available
• When the error is clearly due to a one-time measurement issue
• When a quick correction is needed without generating new data

Step-by-Step Procedure

1. Open the Calibration Window in Clarity.
2. Navigate to the specific compound tab where the error occurs.
3. Locate the calibration level to be excluded.
4. Uncheck the Used checkbox for that calibration level.

Once unchecked, the calibration point is excluded from curve fitting, and the curve automatically recalculates.

3. Method 2: Recalibrating the Level (Recommended)

Why This Method Is Preferred

Recalibration ensures that the dataset fully reflects actual instrument response. It is the most scientifically robust option because it replaces the inaccurate point with new, valid data.

Preparatory Settings

1. Open Calibration Options.
2. Set the Recalibration Mode to Replace.
   • This ensures that the new measurement overwrites the faulty calibration point.
   • For a comprehensive description, see How to Modify Calibration Settings in related Clarity documentation or video tutorials.

4. Recalibration Procedure: Step-by-Step

Step 1: Open Single Analysis

Navigate to Single Analysis mode in Clarity.

Step 2: Select the Appropriate Method

Load the method associated with the existing calibration curve.

Step 3: Change the Sample Type

Set Sample Type = Standard.

Step 4: Assign the Calibration Level

Specify which calibration level should be remeasured (e.g., Level 2).

Step 5: Send and Run the Method

1. Send the method to the instrument.
2. Inject the calibration standard corresponding to the selected level.
3. Run the analysis.

Clarity automatically replaces the faulty calibration point with the new measurement and recalculates the curve.

5. Verifying the Calibration Update

After the chromatographic run finishes:

1. Return to the Calibration Window.
2. Confirm that recalibration has been applied.
3. Inspect the updated calibration curve visually.
4. Click the three-dot icon in the row of the recalibrated level to view detailed calibration point information, including:
   • Detector response values
   • Concentrations
   • Retention times
   • Fit parameters

In the example provided, the curve shows a significantly improved linearity after recalibration.

6. Discussion: Choosing the Right Approach

Removing the Point (Fast Fix)

• Quick adjustment
• May reduce calibration accuracy
• Should be used only when standard remeasurement is not feasible

Recalibrating (Best Practice)

• Scientifically sound
• Ensures a fully validated calibration dataset
• Suitable for GLP- and GMP-compliant workflows
• Preferred for regulated environments

Whenever possible, recalibration should be performed instead of removing calibration points.

Conclusion

Correcting a single calibration level in Clarity software is a straightforward process when using the tools available for point removal or recalibration. By following the systematic steps outlined above, analysts can maintain robust, accurate calibration curves that support high-quality analytical results.

Regular verification of calibration performance is essential for maintaining instrument accuracy, particularly in quantitative chromatographic applications.

For more instructional resources, refer to Clarity’s official YouTube channel and software documentation.