How to Extract UV Spectra From Multiple Peaks in One Step in OpenLab CDS

This Information Applies To: Agilent OpenLab CDS (Rev. 2.x) 

Issue

This article outlines the step-by-step instruction on how to extract UV spectra from multiple peaks in one step. 

Background

If your data contains UV spectral data, you can extract spectra from your chromatogram. You can either:

• Extract a UV spectrum via a right click
• Extract a UV spectrum or multiple spectra using the spectrum extraction tool.
   

Requirements

• Acquisition method in DAD is set to store All spectra see Figure 1. You can read more about parameter settings to store spectra here.

  
  Figure 1: Store All Spectra setting in acquisition method for DAD

• The injection is linked to a processing method that supports manual UV spectra extraction 3D UV Quantitative (Figure 2) or LC/MS Sample Purity (Figure 3).

  Figure 2: 3D UV Quantitative Processing Method

  Figure 3: LC/MS Sample Purity Processing Method

• Under Chromatogram Properties > Spectrum extraction, the Allow to drag range check box is selected. (Figure 4) 
  

  
  Figure 4: Allow to drag range check box

• To be able to carry out the procedure as described, the user needs the privileges Data Processing > Do manual spectrum extraction; Processing Method > Edit spectrum extraction parameters and Processing Method > Edit spectra parameters. Privileges are configured in the Control Panel.

Steps to Follow

1. (Optional) Extract UV background spectrum (see article How to Extract a UV Background Spectrum in OpenLab CDS)
2. In the Chromatograms window, click icon in the toolbar to start the spectrum extraction tool. See How to Extract a UV Spectrum with the Spectrum Extraction Tool in OpenLab 2.x. 
3. Click the chromatogram and drag the mouse over a range that includes multiple peaks.
4. In the confirmation dialog box, choose to extract spectra for all included peaks, and click icon or press [ENTER] to confirm (Figure 5). The apex or average spectra for all included peaks are extracted.
   
   
   
   Figure 5: Confirmation dialog box of extracting spectra of multiple peaks
   
   
   Figure 6 shows an example of how to extract UV spectra of six peaks (with UV background subtraction). 
   
   
   
   Figure 6: Extract UV Spectra in One Step

You can also extract a UV spectrum right-clicking a peak. See article How to Extract a UV Peak Spectrum Via Right Click in OpenLab CDS  

Learn how to effectively operate your Agilent OpenLab CDS Software: HPLC-OLII-1121e - Agilent Infinity LC Systems with OpenLab CDS – Acquisition Method e-learning course available from Agilent education