Biochemical Toxicology scientist loading a sample in HPLC NMS/MS. Liquid chromatography-mass spectrometry (LC-MS, or alternatively HPLC-MS) is a chemistry technique that combines the physical separation capabilities of liquid chromatography (or HPLC) with the mass analysis capabilities of mass spectrometry. 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.