A simple and fast method of solid phase extraction (SPE) disk for the determination of trace acrylamide was developed. Using this new technique along with high performance liquid chromatography (HPLC) and ultraviolet spectroscopy (UV) detection, the feasibility of SPE disk method for rapid enrichment was demonstrated in the determination of trace acrylamide in 500 mL tap water. Active carbon was chosen as the adsorbent to be incorporated into the SPE disk as it gave the best adsorption efficiency.

Another material under investigation for preparing plasma samples is diatomaceous earth or diatomite-like substrate. The porous and channel structures of diatomite offer excellent dispersive properties to trap large molecules such as phospholipids. When a plasma sample passes this specially treated diatomite material, it will spread and penetrate into the pores, to form an aqueous film on the surface of the packing. When a water-immiscible liquid is passing through the diatomite, LLE occurs on the solid support. The procedure is called supported liquid extraction (SLE).