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• Hi, I have a problem with NMRPipe. I have to suppress more than one signal in a DQF-Cosy spectrum, I have suppressed the solvent signal but I m not able to
Message 1 of 2 , Oct 5, 2004
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Hi,
I have a problem with NMRPipe.
I have to suppress more than one signal in a DQF-Cosy spectrum, I have
suppressed the solvent signal but I'm not able to suppress the other ones.
How can I do?
Thank you
Marianna
• Many greetings. It s possible to supress more than one signal region by a series of first-order time domain corrections, each of which corresponds to a shift
Message 1 of 2 , Oct 5, 2004
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Many greetings.

It's possible to supress more than one signal region by a series
of first-order time domain corrections, each of which corresponds
to a shift in the frequency domain. The trick is to find out how
much to shift the data. You can do this by inspection of the spectrum
without any suppression.

For convenience, the phase correction function PS has arguments
for "right shift" and "left shift".

So, if you had one signal that was 10 points from the center of
the spectrum, and another that was 15 points from the center,
these commands in the time-domain would be used:

| nmrPipe -fn PS -ls 10 \
| nmrPipe -fn SOL \
| nmrPipe -fn PS -rs 10 \
| nmrPipe -fn PS -ls 15 \
| nmrPipe -fn SOL \
| nmrPipe -fn PS -rs 15 \

same as

| nmrPipe -fn PS -ls 10 \
| nmrPipe -fn SOL \
| nmrPipe -fn PS -ls 5 \
| nmrPipe -fn SOL \
| nmrPipe -fn PS -rs 15 \

Note that the "center" of the spectrum is point N/2 + 1,
for example point 257 of 1 to 512.

From the "nmrPipe" manual page:

In this DQF-COSY example, time-domain phase correction is
used to shift the solvent signal closer to zero frequency,
where it can be removed more effectively by time-domain con-
volution. After this, the shift is removed by a second
phase correction, and a tentative linear baseline correction
is performed after the transform of the acquisition dimen-
sion. A more thorough correction is made after the 2D
Fourier processing is done:

#!/bin/csh

nmrPipe -in dqcosy.fid \
| nmrPipe -fn PS -ls 9 \
| nmrPipe -fn SOL \
| nmrPipe -fn PS -rs 9 \
| nmrPipe -fn SP -off 0.5 -end 0.98 -pow 2 -c 0.5 \
| nmrPipe -fn ZF -auto \
| nmrPipe -fn FT \
| nmrPipe -fn PS -p0 255.6 -p1 78.0 -di -verb \
| nmrPipe -fn BASE -nw 3 -nl 0% 5% 95% 100% \
| nmrPipe -fn TP \
| nmrPipe -fn SP -off 0.5 -end 0.98 -pow 2 -c 0.5 \
| nmrPipe -fn ZF -size 2048 \
| nmrPipe -fn FT \
| nmrPipe -fn PS -p0 -90 -p1 0 -di -verb \
| nmrPipe -fn TP \
| nmrPipe -fn POLY -auto -xn 5.3ppm \
| nmrPipe -fn POLY -auto -x1 5.1ppm \
-out test.ft2 -verb -ov

On Tue, 5 Oct 2004, marinmrpipe wrote:

>
>
>
> Hi,
> I have a problem with NMRPipe.
> I have to suppress more than one signal in a DQF-Cosy spectrum, I have
> suppressed the solvent signal but I'm not able to suppress the other ones.
> How can I do?
> Thank you
> Marianna
>
>
>
>
>
>
>
>
>
>