A model for the analytical supercritical fluid extraction (SFE) tests from solid samples in which desorption of the solute from the surface of the solid is the rate determining step is presented. The desorption process is described by the Langmuir kinetics. The two stages of the test (static and dynamic) are modeled, where each of the two phases (solid and supercritical fluid) are considered well mixed. The resulting ordinary differential equations are solved analytically for the static stage and numerically for the dynamic stage. Dimensionless curves of concentrations of the two phases and fractional recovery during the two stages of the tests are predicted. These curves are characterized by two dimensionless parameters for the static stage, the equilibrium constant and the fractional initial capacity, in addition to one parameter for the dynamic stage, the desorption coefficient. The model provides a good fit to experimental results for SFE from solids. The trends in the fitted parameters with respect to pressure and temperature are in agreement with theory.