Standard ¹³C sensitivity test sample: 10% Ethylbenzene in chloroform-d.

Insert the sample (ij).

Choose the solvent deuterium signal with the lock command

Tune and match the probehead (wobb or atma if required).

Optimize the shim procedure (read an optimized shim file with the rsh command or performs a gradshim if required).

Record a conventional ¹H spectrum.

Record a conventional ¹³C spectrum.

The calibration of the ¹³C sensitivity test is performed using the standard ¹³C parameter set (the pulse program is set to pulprog zgdc). This test is also a very critical test of the decoupler efficiency. 

The sensitivity is measured on the highest line in the aromatic part of the spectrum according to the equation:
 
                                       S/N=2.5*(height of aromatic)/(peak to peak amplitude of noise)

Update the corresponding pulses and power levels in the acquisition parameters according to the selected solvent/probehead parameters by executing the getprosol command (pulses and power levels must be correctly set by the edprosol command). If required, any acquisition parameter can be modified manually or in the AcquPars section. It is very important to use a long recycle delay, usually d1=5*T1(¹³C) (for instance d1=300 s).

Set p1 to the 90º ¹³C observe pulse at high power level pl1. If required, the CPD ¹H pulses from the decoupler should be recalibrated.

Start acquisition by rga and zg (the expected experimental time is displayed with the expt command).

The recorded data is Fourier transformed with ft (or ef) and phase and baseline corrections are performed using apk and abs, respectively. Modify processing parameters if required from the ProcPars section or using the ased command. See spectrum

Use the TOPSPIN plot editor (xwinplot). Plot the spectrum from 200 to 0 ppm using a CY of 12 cm for a standard A4 chart paper. Use sufficient vertical amplitude (min. 1.5 cm) to plot the noise between 120 and 80 ppm.