We are saddened to report the passing of our dear friend, mentor and colleague, Gregory R. Choppin, a founding member of the Editorial Board of Solvent Extraction and Ion Exchange. He passed peacefully October 21, 2015, surrounded by his wife Ann and other family members. Greg was a loving and supportive husband, father and grandfather who inspired his family and his colleagues with his strong ethical perspective, love of learning, sharp wit and zest for life. He was born in Eagle Lake, Texas. Although military service during the post WWII occupation of Japan interrupted his undergraduate studies, Greg completed a B.S. degree, Maxima Cum Laude, from Loyola University (New Orleans) and went on to earn a Ph.D.in Chemistry from the University of Texas. He then began his professional career in nuclear chemistry/radiochemistry/actinide-lanthanide solution chemistry first as a postdoctoral research associate and then as a research scientist at the Lawrence Radiation Laboratory, University of California, Berkeley working with Dr. Glenn Seaborg on the discovery of transplutonium elements. In his work at Berkeley, Greg was recognized as a co-discoverer of Element 101, mendelevium. These studies involved the first “one-atom-at-a-time” experiments which have since populated the periodic table to element 118. During this period, Choppin published with co-author Robert Silva a landmark separation research paper describing the application of alpha-hydroxy isobutyric acid (HIBA) to the cation exchange resin based separation of adjacent trivalent lanthanide ions. The aptly named “BUTT” column approach to lanthanide separation remains a standard method for lanthanide quantification and transplutonium element production 60 years later. Characterizing the chemistry of lanthanide and actinide complexes in solution became a life-long passion for Greg.
In 1956 Greg joined the faculty in the Chemistry Department at Florida State University, where his research focused on the rare earth elements and the radioactive heaviest elements, resulting in the publication of 13 books and more than 500 research papers. During his career at FSU, Professor Choppin mentored more than 50 Ph.D. students and a similar number of postdoctoral research associates. He was a gifted classroom lecturer, often captivating the imagination of non-chemistry majors in his “chemistry for poets” classes. With Professor Jan Rydberg (and others), Professor Choppin co-authored Nuclear Chemistry: Theory and Applications (which morphed into Radiochemistry and Nuclear Chemistry and has seen four publication editions) and co-edited Principles and Practice of Solvent Extraction (in its second edition).
As a teacher and researcher, Greg fostered the careers of innumerable students and formed close enduring relationships with his loyal band of “Choppinites.” His love of teaching was recognized in 1967 by his designation as a R.O. Lawton Distinguished Professor and his receipt of the Manufacturing Chemists Association National College Chemistry Teacher Award in 1979. Greg loved teaching and research so much that he continued to work despite being feted at several retirement parties over the years. Greg enjoyed a rich fulfilling life personally and professionally. His wide-ranging interests included sailing, scuba-diving, history, art, literature, astronomy, photography, bonsai and collecting Uranium glass.
In the course of his long career, Greg’s achievements were recognized through numerous awards and honors, including honorary doctorates from Loyola University and Chalmers University in Sweden, the Humboldt-Stiftung U.S. Senior Scientist Award (1979), the American Chemical Society Award for Nuclear Chemistry (1985), the Seaborg Award in Actinide Separation Science (1989), the Spedding International Award in Rare Earth Science (1996), the Becquerel Medal for Nuclear Chemistry of the British Royal Chemical Society (2000), and the Hevesy Award (2005). The Chemistry Wing of the Science Building at Loyola University bears his name, the “G.R. Choppin Wing,” and FSU created the Gregory Robert Choppin Chair in Chemistry and Biochemistry in his honor.
Professor Choppin was an exceptional mentor to many young scientists, a guardian of scientific integrity, a focused and productive research scientist, and a valued colleague; his influence continues through the values he instilled in those of us who worked with him. Though we will miss his ever present smile, we will never forget his life lessons. Thanks, Greg.
—Professor Ken NashWashington State University andProfessor Mark JensenColorado School of Mines