How to calculate Signal to Noise ratio in Clarity Chromatography Software

Introduction

Signal-to-noise ratio (S/N) is a critical parameter in chromatography for evaluating peak quality and method sensitivity. The Clarity Chromatography Data System (CDS) includes tools that allow users to calculate S/N directly from chromatograms. This guide explains the complete procedure step by step.

Tools and Requirements

• Clarity CDS software with chromatogram visualization enabled
• Chromatogram file containing peaks of interest
• Result Table window for displaying calculated parameters

Step 1: Determining Noise

1. Navigate to the Chromatogram → Noise and Drift menu.
2. Select Noise Evaluation.
3. In your chromatogram, mark an interval that contains only baseline noise (no peaks).
4. The software determines the noise value and displays it above the Result Table.

Step 2: Configuring the Result Table

1. Right-click inside the Result Table to open the local menu.
2. Select Setup Columns to access the configuration dialog.
3. Define a new column:
   • Name: Enter a descriptive label (e.g., S/N).
   • Expression: Input the formula Height / Noise, where Height refers to the peak height and Noise is the variable determined in Step 1.
4. Disable the Calculate Total option, as it is not necessary for S/N.
5. Confirm with OK to save settings.

Step 3: Viewing Signal-to-Noise Ratio

Once configured, the Result Table automatically calculates and displays the signal-to-noise ratio for every detected peak in the chromatogram. This allows rapid assessment of peak detectability and compliance with method validation requirements.

Discussion

The ability to evaluate S/N directly in Clarity provides several advantages:

• Automation: Removes the need for manual calculations.
• Accuracy: Uses consistent baseline noise determination across the chromatogram.
• Validation Support: Helps confirm method sensitivity in accordance with regulatory guidelines (e.g., ICH Q2, USP).

Conclusion

Clarity CDS offers a straightforward workflow to calculate signal-to-noise ratio for chromatographic peaks. By first defining the noise baseline and then configuring a custom result column, users can quickly assess analytical sensitivity and peak quality.

For further learning and tutorials, additional videos are available on the official Clarity YouTube channel.