To improve the sensitivity of NMR signals of particularly hetero-nuclei in the present case and to reduce the amount of solvent required for sample preparation using regular 5 mm NMR tube, we propose a simple, cost-effective sample preparation method for D2O soluble compounds in this article. We perform solvent encoding of the analyte using a combination of immiscible solvents in the NMR tube. We show that by sandwiching a layer of D2O of length 1.8 cm containing the analyte between two non-deuterated solvents (CCl4 at bottom and C6H6 at the top), which are immiscible with the former in a regular 5 mm o.d. NMR tube one can reduce the amount of deuterated solvent and also enhance sensitivity. The total length is still 4 cm (0.55 ml) liquid of similar susceptibility, which prevents the distortions in magnetic field homogeneity and hence produces good quality spectra.