For a pure substance, the spinodal curve is defined as the locus where thermodynamic quantities such as the thermal expansion coefficient alpha(p), the isothermal compressibility kappa(T), and the isobaric heat capacity C-p are expected to diverge. Its location is of particular importance from both practical and theoretical points of view, since it represents the limit beyond which a particular state of matter, in our case the liquid state, can exist or not. In this work, several predictions of the spinodal curve have been tested, compared, and discussed for 2,3-dimethylbutane. The comparison with results found in the literature reveals that some conclusions established here could be of general application.