A solid-phase extraction device utilizing a section of expanded polytetrafluoroethylene (ePTFE) tubing as the stationary phase is disclosed. The microscopic pores of ePTFE tubing are impregnated with a binding agent having an affinity for a target constituent within a matrix. The matrix is prepared and loaded onto the stationary phase of the system. The target constituent is retained by the stationary phase. The constituent is stripped from the stationary phase with a stripping solution, and collected for further analysis or use.