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Hi, I'm trying to perform an NOESYGPPS 1D 1H NMR experiment to suppress water and the ethanol signals in a wine sample, following the protocol described in Godelmann and Monakhova papers.

I perform the experiments on a Bruker Avance III 500 MHz spectrometer with 5 mm PABBO BB-1H/D Z-GRD Z800701/0135 probehead and TopSpin 2.1.

I didn't managed yet because I have some problems:

  1. As the pulse program noesygpps1d is not available in Topspin 2.1 I imported it from Topspin 3

  2. I didn't know exactly what experiment type to use and I choosed SELNO1H (1D NOESY using selective excitation with a shaped pulse) and I then changed the pulse program to noesygpps1d.

  3. I didn't know how to create the 'shaped pulse' which must have the frequency spectrum of the eight highly selective bands to achieve selective suppression of water signal and the seven individual lines of ethanol in the triplet and quartet. I think that I have to use the Shape Tool 'stdisp' or 'st' command line program specifying the eight signals frequencies, using a command like: "st manipulate shapetype offs b pulDur n f1 ... fn" where, double <puldur> = pulDur = length of shaped pulse (in us); int <n> = number of offset frequencies; double <f1> = offset frequency 1 (in Hz); double <fn> = offset frequency n (in Hz). Surely, the frequencies can be specified in an irradiation frequency list (FQLIST) and read from there. But here what 'shapetype' I have to use ? I have chosen 'Squa100.1000', is this Ok or 'Sine1.1000' would be a better choice ? Also the shape pulse duration is not specified but I chose it to be 100ms.

  4. And finally I didn't know where to specify the RF-field strength of ~25Hz for water singlet and of ~4Hz for the individual lines of the ethanol quartet and triplet, for the created shape pulse.

  5. I know that there are also versions of noesygpps1d pulse programs as noesygpps1d.comp1 and noesygpps1d.comp2 (used to suppress up to 20 strong lipids signals) but I didn't have them yet.

I'll really appreciate if you can give me some hints to perform this multiple suppression experiment.

asked Feb 06 at 03:54

Calin%20Floare's gravatar image

Calin Floare
1

updated Feb 06 at 05:15

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