Qualitative Data Analysis

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Qualitative Data Analysis
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In This Section, We Will Discuss

• How to load data files.
• How to use Signal Options for data display.
• How to apply annotation to your chromatogram.
• Ways to identify components in your sample.
• How to check the purity of a chromatographic peak.

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Preferences Signal Options
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Display Files in Navigation Table
Double-click on sequence or Single Runs to
display associated data files.
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Load Signals using Navigation Table
Turn on/off Navigation Table
Right click the mouse anywhere on the row to
activate menu
Click on the to activate signal details
Data review tools
Grouping can be customized
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Load Signals using Menu
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Signal Options
Use Signal Options... to define how you want a
chromatographic signal to look when it is loaded
or reproduced.
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Signal Options Tools
Graphics Task Tool
Separate and Overlay of Signals
Same Scale and each in Full Scale
Compound Names
Retention Times
Baseline
Object Titles
Axis
Print Window
Copy to Clipboard
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Signal Manipulation
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Annotation

• Options
• Font and Style
• Font Size
• Color, Justification, Rotation

• Select New Annotation.
• Click where you want
• the annotation to appear.
• Select Options.
• Type in text.
• Press OK.

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Annotation with Tools
Edit Annotation Add Annotation Draw Line in
Window Move Annotation Delete Annotation
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Peak Identification

• Compare k values of the unknown with standards.
• Spike the sample with a standard.
• Use a fraction collector to obtain the unknown.
• Use a hyphenated technique such as LC-MS.
• Use a diode array to compare spectra of unknowns
  with standards.

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Spike Sample
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Displaying Spectra
Display Spectra
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Displaying Spectra
Resulting Background Subtracted Spectrum
Selected Spectrum and Reference Spectra
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Spectral Task Tools
Select Spectrum at any time position
Select Spectrum at Peak Apex Position
Average a selected set of spectra
Select a set of Spectra of a peak
Select Peak to display Purity
Select Spectrum to set as first reference
Select Spectrum to set as second reference
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Spectral Libraries Principle
Chlortoluron ?
Take peak spectrum
Print match factor
Match 998
Compare with library
250 300
250 300
W a v e l e n g t h (nm)
W a v e l e n g t h (nm)
Library Searching may be performed in an
automated fashion.
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Match Factor Definition
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UV/VIS Spectral Libraries Current Limitations
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Creating a Library
Create a new Library in Data Analysis
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Search Results
Unknown and Library Spectrum Overlaid
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Peak Purity
Assess chromatographic purity by comparing
spectra across the peak.
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Analysis Indicates Peak Purity
Threshold Curve
Spectral Overlay
Similarity Curve
Print
Exit
Purity Information
3-D Display for Selected Peak
Iso-Plot of Spectra for Selected Peak
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Purity Information - Peak Pure
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Analysis Indicates Impurity
Similarity Curve crosses Threshold Curve
Three or more diamonds in red band
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Purity Information - Peak Impure
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Peak Purity Performance
Match factor influenced by

• Compound Specificity
• Spectral Absorption of Matrix Compounds
• Spectral Noise Level
• Spectra Chosen for Comparison

For best results

• Use an intense lamp and clean flow cell
• Select the appropriate flow cell and slit.
• Collect an adequate number of spectra.
• Set the peakwidth on the diode array detector
  screen to the width of the narrowest peak of
  interest.
• Use a sample concentration within the linear
  range of the detector.