qualitative data analysis. 2 in this section, we will discuss: how to load data files. how to use...
TRANSCRIPT
Qualitative Data Analysis
2
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.
3
Preferences – Signal Options
4
Display Files in Navigation Table
Double-click on sequence or Single Runs to display associated data files.
5
Load Signals using Navigation Table
Right click the mouse
anywhere on the row to activate menu
Click on the ‘+’ to activate signal details
Turn on/off Navigation
Table
Grouping can be customized
Data review tools
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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
Same Scale and each in Full ScaleCompound Names
Retention Times
Object TitlesAxis
Separate and Overlay of Signals
Baseline
Print Window
Copy to Clipboard
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Use the Signal Tool set to graphically work with your chromatogram, then select one of the following:Align the x-axis of multiple signals
Align the y-axis of multiple signals
Reset the alignment of your signals
Create a 3D overlay of signals
Mirror signals
Subtract signals
Integrate all chromatograms
Signal Manipulation
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Annotation
Options:Font and StyleFont SizeColor, Justification, Rotation
1. Select New Annotation.2. Click where you want the annotation to appear.3. Select Options.4. Type in text.5. Press OK.
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Edit Annotation
Add Annotation
Draw Line in Window
Move Annotation
Delete Annotation
Annotation with Tools
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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
Analytical Education Center
H5929A 5-04
0 10 20 30 min.7 15 25
* Insulin?
* Spiked with Pure Standard of Insulin
Identification
Not Insulin*
0 10 20 30 min.7 15 25
0 10 20 30 min.7 15 25
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Displaying Spectra
Display Spectra
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Displaying Spectra
Selected Spectrumand Reference Spectra
Resulting Background Subtracted Spectrum
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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 Spectrum to set as first reference
Select Peak to display Purity
Select Spectrum to set as second reference
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Take peak spectrum
Compare with library
Print match factor
Match: 998
Chlortoluron ?
250 300
W a v e l e n g t h (nm)
250 300
W a v e l e n g t h (nm)
*Library Searching may be performed in an automated fashion.
Spectral Libraries: Principle
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Unknown
Standard
Correlation = 0.92399
numerator =
Abs( (2 Abs Abs- * N
/
denominator = *
Match Factor = 1000 * numerator / denominator
1,i 1,i 1,i
Abs = Absorbance
of spectrum 1 at wl i1,i
Abs = Absorbance of spectrum 2 at wl i
2,i
N = number of wavelengths
i=1
i=n
Abs(
(2 Abs Abs- * N
/
2,i 2,i 2,i
i=1
i=n
i=1
i=n
i=1
i=n
i=1
i=n
i=1
i=n
Abs Abs Abs- **1,i 1,i2,i
i=1
i=n
i=1
i=n
i=1
i=n
Abs2,i
2
N o
r m
a l
i z e
d
100
80
60
40
20
0
250 300
W a v e l e n g t h (nm)
S t
a n
d a
r d
(m
Au)
1200
1000
800
600
400
200
0
U n k n o w n (mAu)0 50 100 150
Match Factor: Definition
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UV spectra not very characteristic
UV spectra dependent on mobile phase (pH)
Non-separated compounds give wrong results
Overlay of sample matrix gives wrong results
No spectral libraries available
UV/VIS Spectral Libraries: Current Limitations
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Creating a Library
Create a newLibrary 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
Similarity Curve
Iso-Plot of Spectra for Selected Peak
3-D Display for Selected Peak
Purity Information
SpectralOverlay
Exit
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Purity Information - Peak Pure
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Analysis Indicates Impurity
Three or more diamondsin red band
SimilarityCurve crossesThreshold Curve
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Purity Information - Peak Impure
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Compound Specificity Spectral Absorption of Matrix Compounds Spectral Noise Level Spectra Chosen for Comparison
Match factor influenced by:
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.
Peak Purity Performance