How to process Varian DEPT spectra?

This tutorial will show you how to process a Varian DEPT spectrum. As you well know, the DEPT pulse program in Varian generates a stacked plot with four slices, acquired with phase of the last pulse equal to 45, 90, 90, 135 degrees.

When you load this kind of spectra into Mnova, you will obtain something like this (if in the 'File/Preferences/NMR/Import' you have the VnmrJ DEPT processing unchecked):

As you can see, you will have in the first slice (red slice with final pulse: 45 degrees) all the protonated signals, in the second and third slices you will get only the CH signals up and in the forth slice (purple slice with final pulse of 135 degrees) a spectrum with the CH and CH3 up and the CH2 down

Then, please make sure that the phase of all the slices is right. If not, you will need to apply a phase correction. We recommend you to select 'Active spectrum' from the stacked ribbon toolbar:

While working on this mode, you will see on the screen just the active spectrum (the spectrum which is highlighted in green in the stacked plot). Should you want to move to another spectrum without resorting to the stack mode just press Shift+Mouse Wheel or Shift + Up/Down keys.

Finally, follow the menu 'Tools/NMR Tools/DEPT Traces':

After having applied the script, you will obtain all the protonated carbons in the first slice (red), the CH in the second slice (green), the CH2 in the third one (blue) and the CH3 in the forth slice (purple), as you can see in the picture below:

Please bear in mind that the relative intensities of the signals are not exactly the same in all the slices, so it is possible that you get small residues in some of the slices.

You could also use the Arithmetic feature to process your Varian DEPT spectra, by following the menu 'Analysis/More Tools/Arithmetic' and enter the following formula:

Please bear in mind that you can save this formula by using the 'Save' button .

If your dataset shows eight spectra means that it contains two arrayed variables "mult" and "qphase".

The arrayed variable mult '0.5 1 1 1.5' refers to the type of DEPT spectrum, in this case DEPTQ 45º, DEPTQ 90º, DEPTQ 90º and DEPTQ 135º, respectively

The arrayed variable qphase '1 -1' refers to the sign of the quaternary carbons + and -, respectively.

This is the meaning of the eight spectra:

spectrum1: +CH + CH2 + CH3 + Cq (deptq45 qphase 1)

spectrum 2: +CH + CH2 + CH3 -Cq (deptq45 qphase -1)

spectrum 3: +CH 0 0 +Cq (deptq90 qphase 1)

spectrum 4: +CH 0 0 -Cq (deptq90 qphase -1)

spectrum 5: +CH 0 0 +Cq (deptq90 qphase 1)

spectrum 6 : +CH 0 0 -Cq (deptq90 qphase -1)

spectrum 7 : +CH -CH2 +CH3 + Cq (deptq135 qphase 1)

spectrum 8 : +CH -CH2 +CH3 - Cq (deptq135 qphase -1)

By doing aritmetics with the 8 spectra you can obtain the edited spectra.

For instance the following combinations:

Only Cq: 1 -2 +3 -4 +5 -6 +7 .7

Only protonated carbons: 1 + 2

Only CH = 3 +4 +5 +6

Only CH2 = 1 + 2 -7 - 8

All carbons = 1

You will be able to process those datasets by following the menu 'Tools/NMR Tools/DEPT traces'.

After having run the script, a phase correction may be needed. If you need to apply a different phase correction for each trace, just hold down the Alt key and click on the desired trace (or open the Stacked Items Table) to finally correct the phase:

After having corrected the Phase to all the traces, this will be the result (from up to down: CH3, CH2, CH, quaternary and All carbons):