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Qualitative Data Analysis. 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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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.
Display Files in Navigation Table Double-click on sequence or Single Runs to display associated data files.
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
Signal Options Use Signal Options... to define how you want a chromatographic signal to look when it is loaded or reproduced.
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
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
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.
Annotation with Tools Edit Annotation Add Annotation Draw Line in Window Move Annotation Delete Annotation
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. Peak Identification
Displaying Spectra Display Spectra
Displaying Spectra Resulting Background Subtracted Spectrum Selected Spectrum and Reference Spectra
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
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.
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
Creating a Library Create a new Library in Data Analysis
Search Results Unknown and Library Spectrum Overlaid
Peak Purity Assess chromatographic purity by comparing spectra across the peak.
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
Analysis Indicates Impurity Similarity Curve crosses Threshold Curve Three or more diamonds in red band
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.