Community Leaders: Gary M. Hieftje

This issue of Journal of Analytical Atomic Spectrometry contains manuscripts submitted by a large number of distinguished researchers to honor the contributions of Professor Gary M. Hieftje to the field of atomic spectrometry. This special issue is one of a series that are dedicated to community leaders in our field with the intent of providing special recognition to those individuals that have shaped the future of atomic spectrometry through their example of research brilliance, commitment to education, selfless service, and the dedication with which they have served this journal. Without doubt, Professor Hieftje embodies the best of these qualities, and the excellence and number of the manuscripts contributed to this issue are recognition of the influence that Professor Hieftje has had on the international community. We are proud to introduce this special issue prepared in his honor.

Professor Hieftje has built an international reputation for research excellence and leadership in the field of atomic spectrometry over a career that spans more than 50 years. Gary M. Hieftje earned his Ph.D. from the University of Illinois in 1969 under the direction of Professor Howard V. Malmstadt, and joined the faculty of the Department of Chemistry at Indiana University in Bloomington, Indiana in the same year. This home was to prove to be an exceptionally good one for Gary, and he was to spend the entirety of his independent research career at IU. He became a full professor in 1977, was named a Distinguished Professor in 1985, and named the Robert and Marjorie Mann Chair of Chemistry in 2000, retiring to emeritus status in 2019. Over this long and fruitful time, Professor Hieftje worked tirelessly to build the Laboratory for Spectrochemistry, a research environment and laboratory that would become a center of atomic spectrometry research.

Professor Hieftje began his research career in the field of atomic spectrometry and has remained within this research community for the entirety of his career until the present day. Professor Hieftje’s Ph.D. thesis, “A Unique System for Use in Studying Flame Spectrometric Processes”, described a single-droplet sample introduction system that he used to gain valuable insights into the mechanisms relevant to analytical flames used in atomic absorption spectrometry (AAS). This mixture of fundamental experimental study in service of analytical chemistry goals was to become one of the trademarks of Professor Hieftje’s research approach, and it is notable that these same themes of single-droplet analysis and fundamental scientific pursuit remain as relevant in current research as they were when the work was done almost over a half-century ago.

Professor Hieftje continued to explore practical and experimental aspects of flame-AAS throughout his early independent research career at Indiana University. The research themes for which he was to become internationally renowned are evident in these early publications; however, they also presage his broadening research interests in analytical chemistry. Early publications dealt with signal-to-noise theory, modulation and correlation measurement approaches, instrumental design, and new and improved measurement strategies, and while most of these publications are focused on applications in atomic spectrometry, it is also clear that his research interests were continually broadening. Indeed, while our community is most familiar with Professor Hieftje’s work in atomic spectrometry, it is worth noting that he has also made significant contributions to the fields of fluorescence spectroscopy, molecular mass spectrometry and ionization schemes, near-infrared spectroscopy, computer data acquisition and chemometrics, separation science, chemical sensors, and LASER spectroscopy. Gary is also known across the broader field of analytical chemistry for his philosophical tenets regarding instrumental development, and as a strong proponent of the critical role of this activity in analytical chemistry development. In all of these activities you will find several common themes: an insatiable curiosity, deep and well-considered logical development, crystal-clear explanation, a visionary ability to presage important future areas, and a creative knack for developing new approaches to solve problems in analytical chemistry.

Professor Hieftje has a substantial record of research. He has thus far published 608 manuscripts in the international peer-reviewed literature, authored 13 books and 21 book chapters, and holds 22 patents. This research history touches a wide swath of atomic spectroscopy, including substantial contributions to the development of flame atomic absorption spectrometry, inductively-coupled plasma atomic emission spectrometry, inductively-coupled plasma mass spectrometry, glow discharge spectrometry, microwave atomic emission spectrometry, fundamental plasma spectrochemistry, and many other areas. Attempting to catalog the entire list here is not feasible, and attempting to highlight one area aside from all the others is difficult because it runs the risk of missing one of the key contributions by omission, or undersells the profound influence of decades of work in any of these categories. Therefore, a better approach might be to select a pair of themes that are common to much of his research in atomic spectroscopy and that we believe provide a bit of insight into his influence and research philosophy.

One theme that is evident throughout Professor Hieftje’s career is a philosophy that pursuing a fundamental understanding is the best strategy to develop a solution to the problem at hand. Time that is spent in the laboratory studying the basic, fundamental mechanisms is time well spent, and it is effort that will eventually lead to better and more permanent advances for the field of analytical chemistry. Whether in the areas of signal-to-noise theory, plasma spectrochemistry, spectroscopy, or instrumental development, the pursuit of fundamental understanding through experiment is a hallmark of his work. Perhaps nowhere is this better demonstrated than in his contributions to the fundamental characterization of the analytical inductively-coupled plasma. Professor Hieftje developed and refined several spectroscopic experiments over the course of 30 years to produce high-fidelity measurements of the fundamental plasma conditions in the analytical ICP. Through point-by-point spectroscopic analysis, including early Thompson scattering measurements of electron density and temperature, the comprehensive 3-dimensional map of the plasma could be created. These long and often difficult experiments provided key insights into the basic mechanisms of the ICP, leading to realizations that could be used to optimize its analytical utility. The lessons learned through this fundamental study of the ICP, and other plasmas, have advanced our understanding and use of these systems.

Professor Hieftje often credits his research advisor, Professor Howard Malmstadt, with a piece of wisdom that he has, in turn, passed on to his own research students: “Define the ideal, and then strive to attain it.” By defining the optimum condition, even in the abstract, one can create a direction for the research and set a benchmark to strive toward even if the goal may be unreachable. The strategy also allows one to test concepts against the reality of the experiment. A great example of this approach comes from his graduate school days in the search for an ‘ideal spark source’ for emission spectroscopy. Reasoning that the ideal spark source would have a very stable voltage source, Gary assembled an enormous battery, made from many individual cells, and used it to construct an ultra-stable high-voltage source; it was so large it had to be moved on a push-cart and so was named the “voltswagon”. While this might not seem to be an entirely practical solution, the approach did permit the study of such spark systems with a ‘more ideal’ voltage source, and thus led to a better understanding of the potential advantages.

The strategy is also evident in Professor Hieftje’s work in the field of ICP-MS, where he has developed several new instruments. Reasoning that the ‘ideal ICP-MS’ would permit the analyst to measure signal from the entire periodic table of the elements and their isotopes simultaneously and rapidly, he has worked to create instruments that would approach this ideal. These included the first ICP-Time-of-Flight Mass Spectrometer (ICP-TOFMS), which demonstrated the advantages of simultaneous multielemental atomic mass spectrometry. The research subsequently generated several TOFMS variants and was used to advantage with different ionization sources (e.g. glow discharges, microwave plasmas, lasers, etc.), a variety of sample introduction devices (e.g. laser ablation and hydride systems), and coupled with chromatographic separations. The pursuit of the ‘ideal ICP-MS’ also led to the development of the first real attempt at a modern direct-reading mass spectrometer, which employed a Mattauch–Herzog mass spectrograph along with a specialized detector technology in order to measure ‘All the Signal All the Time’. More recently, the pursuit of the ideal has also led to the development of the first Distance-of-Flight Mass Spectrometer (DOFMS), a new form of mass spectrometer that is able to separate ions in space according to their m/z. In each case, research developments in pursuit of a lofty goal inspired further refinement that is still ongoing.

The contributions that Professor Hieftje has made to this community, and the high level of his research contributions to the wider field of analytical chemistry, have been recognized through many awards. He received the Robert Boyle Prize for Analytical Science and the Theophilius Redwood Award from the Royal Society of Chemistry, the ACS Award in Analytical Chemistry, ACS Chemical Instrumentation Award, ACS Award in Spectrochemistry, ACS Excellence in Teaching Award, and the ACS Distinguished Service Award, the Lester Strock Medal from the Society for Applied Spectroscopy (twice), the Monie A. Ferst Award of Sigma Xi, the Maurice F. Hasler Award from the Pittsburgh Conference, the Pittsburgh Analytical Chemistry Award from the Society for Analytical Chemists of Pittsburgh, a Humboldt Research Award, the CSI XXXV Award, the IR100 award (three times), the Ron Hites Award from the American Society for Mass Spectrometry, the Winter Conference Award in Plasma Spectrochemistry, and many, many other honors. He was elected a Fellow of the Royal Society of Chemistry, the Indiana Academy of Science, the American Chemical Society, the American Association for the Advancement of Science, and the Society for Applied Spectroscopy. Most recently, Professor Hieftje was also elected Fellow of the National Academy of Inventors in 2018. Even this very partial list is ample evidence of an exceptionally distinguished career.

Professor Hieftje often comments that “the most important product of the research is the student”. To do great research and produce excellent scientists in their own right is certainly a mark of excellence. Professor Hieftje has advised 70 Ph.D. degrees and 27 master’s degrees, and a large number of undergraduates and visiting scientists have performed research in his laboratories. As a gifted teacher, another hallmark of his career is a talent for explanation and communication, and both students and those attending research presentations have enjoyed his crystal-clear and logical presentations. Over the course of his career, he and his students have presented 1017 papers at international research meetings, of which approximately 700 were plenary or invited presentations.

Professor Hieftje has also served this journal with distinction. He has served on the JAAS international Advisory Board continuously from the journal’s founding in 1986 to 2016. He also served on the Editorial Board from 2002–2004 and again from 2008–2016, and as the Editorial Board Chair from 2004–2006. He has contributed over 70 articles to JAAS. Professor Hieftje was also a key contributor to the founding of the Royal Society of Chemistry journal Metallomics, a journal at the forefront of atomic spectrometry.

Over a brilliant research career that includes significant contributions to this community, many students and colleagues also laud Gary’s friendship, mentorship, and collegial selflessness. He is an excellent colleague and boasts lifelong friendships across the field and throughout his professional life. For all of these reasons we know that his career will be one with a lasting influence.

On behalf of the editorial organizers, the Royal Society of Chemistry, the contributing authors, and the wider community, we wish Professor Gary Hieftje a happy retirement filled with many more years of curiosity and scientific interest.

---