One of the most popular types of tandem MS instrument is the triple quadrupole mass spectrometer, invented at Michigan State University by Richard A. Yost (now a chemistry professor at the University of Florida, Gainesville) and chemistry professor Christie G. Enke (now at the University of New Mexico, Albuquerque). James D. Morrison of Latrobe University, Melbourne, Australia, helped Yost and Enke reduce the technique to practice.