Standard ASTM test sample: 60% benzene in Dioxane.

Record a conventional ¹H spectrum.

Record a ¹H-coupled ¹³C spectrum.

The calibration of the ¹³C sensitivity test is performed using the standard C13SENS parameter set (the pulse program is set to pulprog zg) . 

The signal to noise ratio (S/N) is determined on the intensity of the triplet lines of the deuterated benzene according to the equation:
 
                                  S/N=2.5*(height of triplet)/(peak to peak amplitude of noise)

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.

. Reference the central line of the 1:1:1 triplet of the benzene to 128.0 ppm. See spectrum

 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.

Good sensitivity can be obtained with good resolution and good line shape only. The splitting between the lines of C6D6 should go lower than 9%, 10% and 12 % for sample diameters of 5, 10 and 20 mm, respectively.

A correction of the baseline of the spectrum may be necessary if computer calculation of the signal/noise ratio (sino) is executed.