Guohong Zhao has served as Manager of Analytical Development of Tioga Research since September 2019. He has a broad background in analytical and physical chemistry and biochemistry, with over twenty-five years of experience in analytical method development for various products, including food and personal care products, by using variety of modern mass spectrometric techniques (LC-MS/MS, LC/TOF, GC-MS, FTMS, LDI-MS) and chromatographic techniques (HPLC, GC). Guohong has a PhD in Physical Chemistry from Swiss Federal Institute of Technology, Lausanne, Switzerland where his doctoral research focused on studying photodissociation and ion-molecule reactions of isomeric ions by using Fourier Transform Mass Spectrometry (also called Ion Cyclotron Resonance Mass Spectrometry). He then pursued post-doctoral research in the Environmental Analytical Research Laboratory of Texas A&M University at Galveston. He helped establish and managed an analytical laboratory to support clinical metabolism studies while working as a research scientist in Washington University School of Medicine in St. Louis. He joined Unilever as Senior Research Scientist to support formulation development and manufacturing processes for both hair care and deodorant products. Moving to Northland Laboratories (acquired by Matrix Science in 2018) in 2007, he was responsible for analytical method development and validation, problem solving in food testing, and technical reviews and approvals of laboratory daily operations. He has been a member of the American Chemical Society and the American Society for Mass Spectrometry since 1994 and was previously a member of AOAC and IFT.