Xu Li-hua
Carlos VargasThis Information Applies To: Agilent MassHunter Qualitative Analysis Software version 10.0 or higher
Issue
Identifying compounds using a spectral library is essential in qualitative analysis. This article will describe how to load a data file and method, set library search parameters and identify compounds.
Steps to follow
1. Load a data file.
Click File > Open Data File, or click the top-left corner of the toolbar Open data files icon > choose the data file > OK, or double click the data file. In this example, the evaldemo data file is used. When a data file is opened, a total ion chromatogram (TIC) is generated automatically and shown in the Chromatogram Results window. The Data Navigator shows the data file and the TIC.
2. Load a method.
Click Method > Open, Methods for Qualitative Analysis program, by default, are saved in the D:\MassHunter\Methods\X folders (X here is the software version). As an example, we are using the Default-GCMS-SQ.m method, which has parameters optimized for GC/MSD single quadrupole instruments.
3. Specify a library.
Use Navigator View and open the Method Editor (click View > Method Editor) In the Method Editor, Click Identification to access the method parameters for identifying compounds. Learn about Navigator View Introduction the Layout of Agilent MassHunter Qualitative Analysis.
a. Add a library.
Click Identification Workflow, then click Add and select a library. The demo.l library has been added in this example (see Figure 1). You can search over multiple libraries by adding them to the Library selection. The libraries will be searched in the order listed.
b. Library search settings.
Click Library Search Settings, then select each tab and set search options (see Figure 2).
Figure 2. Library search setting
4. Identify compounds.
a. Integrate and extract peak spectra. Click Chromatograms > Integrate and Extract Peak Spectra.
b. Select one or more Spectra (use ctrl-click) to identify when searching the library. Click to access the Library Search Settings in the Method Editor, then click Search Library / DB for Selected Spectra (see Figure 3).
Figure 3. Select spectra to identify
1. Spectra 2. Search library / DB for selected spectra
c. The search results appear in a new window Spectrum Identification Results. The library match score is displayed (in this case, Score 75.29) along with the compound name and molecular formula. You can click tabs at the bottom to switch the window from Spectrum Identification Results to Chromatogram Results (see Figure 4).
Figure 4. Spectra identification result
d. If the molecular structure is available from the library, the structure will appear in the spectrum displayed in the MS Spectrum Results window.
To display this structure at a larger scale, we need to reduce the spectrums displayed by choosing the maximum number of list panes or unselecting spectra (see Figure 5).
Figure 5. MS Spectrum Results
1. Compound molecular structure 2. The maximum number of list panes 3. Select or unselect spectra
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Learn how to effectively operate the Agilent MassHunter software:
Agilent 7000 or 7010 Triple Quadrupole GC/MS with MassHunter Workstation e-learning paths available from Agilent education
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