Systems and methods for extracting an analyte from a sample. The system includes a reaction vessel for receiving the sample and a reaction solution, a mixer for mixing the sample with the reaction solution, a filter and a drain for passing soluble components from the reaction mixture, including the dissolved analyte, from the reaction vessel. A purification vessel is located below the reaction vessel. A selective sorbent is disposed in the purification vessel for retaining contaminants from the soluble components from the reaction mixture and passing a purified analyte. An evaporation container is located below the purification vessel. A heater heats the evaporation chamber and evaporates the solvents from the purified analyte, which can then be quantitatively measured.