Biochemical Toxicology scientist loading a sample in HPLC. Liquid chromatography (LC) is a separation technique in which the mobile phase is a liquid. Liquid chromatography can be carried out either in a column or a plane. Present day liquid chromatography that generally utilizes very small packing particles and a relatively high pressure is referred to as high performance liquid chromatography (HPLC). The National Center for Toxicological Research (NCTR) is FDA's internationally recognized research center. The unique scientific research expertise of NCTR is critical in supporting FDA product centers and their regulatory science roles. NCTR, in partnership with researchers from government, academia, and industry, develops, refines, and applies current and emerging technologies to improve safety evaluations of FDA-regulated products.