Analysis pull-down menu

Calibration is accessible via the Calibration option in the Analysis pull-down menu (Fig. 4.8). Its activation switches the button panel into the Calibration mode, which allows you to select between two different calibration methods. 

In the Analysis pull-down menu choose the Integration option. Clicking on the Automatic button in the corresponding button panel opens a dialog box. Select the Detect Area mode and click on the Execute button to perform an automatic integration. 

The Linewidtli option in the Analysis pull-down menu allows you to measure the linewidths at half height. The ability to recognize different linewidths in your spectrum is important because it may indicate additional molecular processes going on in solution. Broadening of some of the resonances may be indicative of additional non-resolved couplings, dynamic processes or different types of relaxation mechanisms selectively affecting a particular observed nucleus. This option will also be used to estimate linewidths for use as input data for WIN-DAISY as described in detail in Modem Spectral Analysis, volume 3 of this series. 

Load the proton spectrum of peracetylated glucose D NMRDATA GLUCOSE 1D H GH 002999,1R and expand a methyl resonance. From the Analysis pull-down menu choose the Linewidth option. With the cursor in Maximum Cursor mode, select a resonance line by clicking the left mouse button. With the cursor set on the top of the peak, click the right mouse button. A horizontal line indicates the intensity at half height and the corresponding line width (in Hz) will appear below the title bar. 

Enter 2D WIN-NMR and select an expansion showing the diagonal peak (in the homonuclear case) or the cross peak ( in the heteronuclear case) of the same signal and calibrate it accordingly with respect to Fl and F2 using Manual Calibration in the Analysis pull-down menu. 

Since integration is less common with 2D spectra only a short overview of the features in 2D WIN-NMR will be given. Activating the Manual Integration option in the Analysis pull-down menu changes the buttons menu on the lower part of the button panel (Fig, 4.28). 

In NMR-SIM spectrum calibration is not normally necessary, since the chemical shifts in the spin system file are already defined on the ppm scale. However occasionally it might be necessary to calibrate a spectrum, particularly if comparing a simulated spectrum with an experimentally measured spectrum. In ID WIN-NMR the calibration mode is selected by choosing the Calibrate command in the Analysis pull-down menu. The calibration can be performed in two ways ... 

To start the analysis the Multiplets command is selected from the Analysis pull-down menu. With the mouse cursor in maximum cursor mode the cursor is positioned on top of one of the signals making up the multiplet. The mouse cursor is fixed in position by clicking the left mouse button. Clicking the right mouse button in the main window opens a pop-up menu where it is possible to chose the number of equidistant lines which should be assigned (Free gridi 2 Distances, for instance). 

Even though the NMR-SIM spin system files are defined using chemical shift values instead of frequency values, occasionally it is necessary to calibrate the second dimension (fl). In 2D WIN-NMR the calibration is enabled using the Manual calibration command of the Analysis pull-down menu. In the calibration mode the standard mouse cursor is replaced by a crosshair which is positioned on a signal of known chemical shift. Clicking the left mouse button fixes the cursor position and opens a dialog box where the appropriate chemical shift values can be entered in both dimensions. The Ok button closes the dialog box and starts the calibration. 

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