SEN 13 C spectra were also recorded on a mixture of four amino acids SEN (in 1.8 cm) using TLIS comprising of CCl4/25%D2O & 75% H2O/ C6H14-where the middle layer is a mixture of solvents 25%D2O & 75% H2O. Compared to the S:N from the standard sample of 4 cm, the 13 C signal from the AA mixture in SEN 1.8 cm sample showed S:N improvement by a factor ranging from ≈2 to 3.5 as displayed in Figure and. Table . Comparison of the 13 C S/N values at 800 MHz for the peaks labeled as 1 to 5 in Figure for the 4 cm standard and 1.8 cm (CCl4/D2O/C6H12) respectively. The sample is 4 mg sucrose. ). When compared at same signal height, the noise level is higher in the standard sample; panel C on the right displays this comparison. Table . Comparison of the 13 C S/N values of the peaks labeled as 1 to 6 in Figure for the 4 cm standard (1:3=D2O:H2O) and SEN 1.8 cm (CCl4/1:3=D2O:H2O/C6H12) samples respectively for a mixture of four amino acids.