Gary Hieftje: Pioneering Analytical Chemistry and Nurturing Future Scientists

Spectroscopy is publishing a series of feature articles highlighting the lives and careers of the most influential spectroscopists over the past 100 years. These individuals were selected by our Editorial Advisory Board and the editors to represent the leading figures in spectroscopy over the century. Our first featured Icons of Spectroscopy Laureate is Professor Gary Hieftje.

Gary Hieftje

Gary Hieftje’s scientific journey began at the young age of 10, and was inspired by his neighbor, Marvin Overway, the chemistry teacher at Zeeland High School in Michigan. Overway fueled Hieftje’s interest by providing reagent bottles, elemental mercury, chemicals, and outdated textbooks, leading to inventive experiments such as “super gunpowder.” Hieftje’s early adventures in chemistry, including an aromatic substitute for sulfur and the discovery of potassium perchlorate, formed the foundation of his scientific curiosity.

Graduating from Zeeland High School in 1960 with a strong science and math background, financial constraints redirected Hieftje to Hope College, where he earned an A.B. degree in chemistry in 1964. Juggling scholarships, part-time jobs, and research under Gerrit Van Zyl’s guidance, Hieftje’s academic journey at Hope College paved the way for his future in analytical chemistry.

Encouraged by Van Zyl, Hieftje applied to the University of Illinois, initially intending to major in inorganic chemistry. Financial challenges first led him to the Illinois State Geological Survey, where he conducted research in physical chemistry, resulting in publications in Analytical Chemistry. Eventually, in 1965, Hieftje joined the University of Illinois, majoring in analytical chemistry under Howard V. Malmstadt. His doctoral research, guided by Malmstadt, focused on time-resolved high-voltage spark emission spectrometry and the development of an isolated droplet generator. The collaboration led to publications, and laid the groundwork for Hieftje’s future contributions to flame spectrometric processes. In 1969, Hieftje earned his Ph.D., acknowledging Malmstadt’s influence on his teaching, research, and service philosophy.

Hieftje’s academic legacy continued at Indiana University, where he began his teaching and research career in 1969. Over the next five decades, he achieved numerous accolades, for research, teaching, and inventions.

As of 2018, Hieftje had entered emeritus status at Indiana University, with an impressive record of over 600 publications, 13 books, 20 book chapters, 21 patents, 27 named lectureships, and many of the most prestigious awards in analytical chemistry. His impact extended to mentoring 70 doctoral students, numerous master’s students, and countless undergraduates and visiting scientists (1,2).

Throughout his career, Hieftje received prestigious awards for teaching, research, and contributions to analytical chemistry. His recognition includes fellowships in various scientific societies, such as the American Chemical Society, the Royal Society of Chemistry, and the National Academy of Inventors.

Gary Hieftje’s journey from a curious 10-year-old experimenting with “super gunpowder” to a distinguished analytical chemist reflects a lifelong commitment to scientific excellence, innovation, and mentorship.

Research Impact

Hieftje’s impact as a scientist defies easy assessment, prompting inquiries into his greatest contributions. Colleagues and former students, including Richard Russo, Paul Farnsworth, Radislav A. Potyrailo, Scott D. Tanner, John Olesik, Norbert Jakubowski, Alfredo Sanz-Medel, Ron Hites, Maria Montes-Bayón, Carsten Engelhard, George Chan, and Robert Lodder, grappled with this question, emphasizing Hieftje’s multifaceted influence.

Russo highlighted a 1969 paper coauthored with Hieftje, establishing the controlled stream of uniform-sized droplets for atomization in flame spectrometry as foundational (3). Farnsworth underscored the enduring impact of Hieftje’s early work on droplet and particle evaporation in flames, later contributing to the fundamental study of analyte behavior in inductively coupled plasma (ICP).

Potyrailo acclaimed Hieftje’s instrumental developments, asserting that they propelled atomic analytical instrumentation science to new heights. Tanner praised Hieftje’s insightful papers on plasma characteristics, ion sampling, ion optics, and his work on time-of-flight mass spectrometry. Olesik commended Hieftje’s dedication to challenging projects, resulting in breakthroughs such as single-droplet measurements in flames and innovative instruments like the first ICP-time of flight mass spectrometer (ICP-TOF-MS).

Jakubowski emphasized instrumental innovations as a major contribution, including pioneering work in ICP-TOF-MS, improvements in ICP-MS, distance of flight (DOF)-MS, and applications coupling these instruments with various techniques. Sanz-Medel deemed Hieftje a visionary for reliable instrumental chemical analysis, emphasizing his pivotal role in defending the need for fundamental discovery and study.

Hites noted the remarkable breadth of Hieftje’s work, spanning droplet generation, optical spectroscopy, ICP generation, and mass spectrometry, describing his approach as Edisonian. Montes-Bayón acknowledged Hieftje’s exceptional scientific productivity and evolving communication skills, making his talks both informative and insightful.

Engelhard praised Hieftje for brilliant scientific work in the lab, emphasizing his impactful interactions and inspiration that encouraged others to pursue independent careers. Chan lauded Hieftje’s greatest contribution as the training of the next generation of scientists, highlighting the superb mentorship that encompassed scientific knowledge, critical thinking, and independent research skills.

Lodder echoed the sentiment that Hieftje’s students represent his greatest contribution, emphasizing the numerous newly minted scientists making diverse contributions to the field. In essence, Hieftje’s influence extends beyond scientific achievements to include mentorship, innovation, and the development of a legacy of scientists shaping the future of analytical chemistry.

Educator

Hieftje’s profound impact as an educator extends to undergraduate and graduate education, influencing students beyond specific scientific concepts and imparting broader lessons about the passion for science, dedication to excellence, pragmatic approaches to experimental precision, and fostering an environment of research freedom, leadership, and personal development, all while approaching science with joy and a “work hard/play hard” attitude. This can be attested to by former students and mentees like Steven Ray, Richard Russo, Robert Lodder, Carsten Engelhard, Radislav A. Potyrailo, Gerardo Gamez, and Maria Montes-Bayón. Former graduate student Steven Ray emphasizes Hieftje’s gift for explaining complex concepts in a straightforward and logical manner, underlining the meticulous preparation behind seemingly effortless classroom lectures.

Hieftje’s influence extends to undergraduate education through the widely used textbook, “Chemical Separations and Measurements” by Peters, Hayes, and Hieftje (4). The book has become a foundational resource for introductory undergraduate courses in analytical chemistry.

Former students emphasize that beyond specific scientific concepts, Hieftje imparted broader lessons about the passion for science. Richard Russo reflects on Hieftje’s dedication to excellence, instilling a commitment to detailed descriptions through exceptional writing and speaking skills. Russo acknowledges Hieftje’s pivotal role in paving the way for successful careers in science for each student that Hieftje mentored.

Robert Lodder recalls valuable offhand comments by Hieftje, emphasizing the significance of becoming famous among a close-knit scientific community rather than seeking widespread recognition. Lodder also recounts Hieftje’s advice on data collection, urging a pragmatic approach to experimental precision.

Carsten Engelhard shares his initial trepidation upon meeting Hieftje, a renowned figure in the field, highlighting Hieftje’s welcoming demeanor and the emphasis on enjoying scientific work as a form of fun.

Hieftje’s teaching philosophy goes beyond instruction, fostering an environment where students are viewed as peers with research freedom. Radislav A. Potyrailo praises Hieftje’s leadership style, characterized by guidance, true research freedom, and encouragement for personal development within the group.

Despite his significant contributions, Hieftje approached science with joy, a strong work ethic, and time for fun, as noted by Gerardo Gamez. Colleagues admire Hieftje’s infectious enthusiasm, describing it as a key factor in inspiring passion and deep understanding among students.

Maria Montes-Bayón recounts Hieftje’s ability to engage students even outside their primary research disciplines, highlighting his impressive interactions with young generations.

Hieftje’s legacy extends through his students, who are now influential figures in academic institutions. Graduates of his mentorship and teaching continue to produce scientific achievements, forming a network of prolific scientific “grandchildren.”

Research

Hieftje’s illustrious career is marked by abundant research contributions spanning five decades, leading to groundbreaking developments in chemical instrumentation and measurement science. As a mentor, Hieftje’s innovative approach is evident in his abundance of research ideas, fostering an environment where students can explore diverse projects.

The trajectory of research in the Hieftje laboratory evolved from early investigations into droplets to fundamental studies on atom formation in analytical flames and plasmas. The group then delved into signal-to-noise enhancement, employing computer algorithms for improved instrument performance and signal processing. Hieftje’s notable contributions include advancements in signal-to-noise theory, modulation approaches, and the integration of computers in the laboratory.

Throughout the 1970s, the laboratory explored diverse topics, including computer-controlled microwave discharge emission spectrometry, flame emission, atomic absorption, atomic fluorescence, laser mode noise, picosecond luminescence lifetimes, and microwave-induced plasmas. The 1980s witnessed further advancements, such as computer-aided identification of infrared spectra and the development of miniature ICP torches.

Hieftje’s impact extended into various analytical techniques, including flame and furnace atomic absorption spectroscopy (AAS), ICP–optical emission spectrometry (ICP-OES), ICP-MS, ICP-TOF-MS, laser-induced breakdown spectroscopy (LIBS), and more. His students explored phenomena like gas flow dynamics, droplet generation, plasma formation, fluorescence interference, and ion sensing.

Simultaneously, the laboratory contributed to the design and development of essential instrument components, ranging from lasers and detectors to electronics and optical elements. Hieftje’s group applied these techniques to diverse analytical challenges, including metallomics, inorganic mass spectrometry, trace metals, cholesterol determination, solute vaporization rates, and multielement analysis.

Noteworthy projects included the development of a surface-wave-induced plasma source (surfatron) for atomic emission spectrometry and a chemometric method known as the Bootstrap Error Adjusted Single-sample Technique (The Quantile BEAST), a multivariate chemometric method for detecting “false” or unrepresentative samples in a multivariate calibration training set.

The Hieftje laboratory’s contributions underscore a commitment to advancing the science of instrumentation and measurements. Their extensive exploration has left an indelible mark on elemental and molecular analysis, showcasing Hieftje’s dedication to pushing scientific boundaries and inspiring future generations of practicing scientists and teachers.

Inventions

Hieftje has made significant contributions to academia, particularly through a series of inventions spanning multiple disciplines. Hieftje’s inventive work encompasses diverse fields, including chemistry, biology, physics, computer science, medicine, and environmental science.

His notable contributions to analytical instrumentation, such as the Smith-Hieftje background correction for atomic absorption and the development of microwave plasma systems, mini-torches for ICP, and focal plane array detectors for ICP-MS, have garnered acclaim in the inventors and scientific community.

Hieftje’s patented inventions have played a foundational role in shaping modern AAS, ICP, and MS methods. Among these patents, the Spectroanalytical system significantly impacted atomic absorption by introducing a log ratio circuit for background correction (5). Another patent addresses accurate dispensing of liquid samples for furnace-AAS (6).

In the realm of near-infrared spectroscopy, Hieftje’s inventions include a method for deriving pure component spectra (7), and another for determining physical properties from near-IR spectra (8). His innovations extend to non-contact attenuated total reflection (ATR) spectroscopy, with a patent addressing the analysis of intact pharmaceutical capsules and tablets (9).

Hieftje’s contributions to mass spectrometry are noteworthy. For instance, one of his patents introduces a vertical rotary spray chamber for aerosol conditioning (10). In time-of-flight mass spectrometry, he devised a correction method for sampling and ion beam collimation (11). Another invention, the solution-cathode glow discharge corrects plasma-related errors in ICP-atomic emission spectroscopy (AES) (12).

In the atmospheric pressure realm, Hieftje’s inventions include an apparatus for ambient mass spectrometry (13), and a flowing atmospheric-pressure afterglow ion source (14). For enhanced mass resolution, the Zoom-TOF-MS device utilizes switchable ion optics (15).

His explorations continue with inventions like a device combining DOF-MS and TOF-MS (16), ideal for examining complex mixtures online. Notably, Hieftje delves into counterfeit electronic component identification (17), offering detailed information in a reduced analysis time.

In essence, Hieftje’s inventive legacy extends beyond analytical chemistry, significantly impacting the landscape of modern instrumentation and methodologies, and earning him recognition as a Fellow of the National Academy of Inventors.

Legacy

A luminary in analytical chemistry, Hieftje has left an indelible mark on the scientific community through groundbreaking inventions and dedicated mentorship. Renowned for his diverse contributions spanning chemistry, biology, physics, and more, Hieftje’s impact extends beyond research into the realm of where he fostered a familial atmosphere within his research group and beyond.

Eyal Elish, a researcher at the Negeve Nuclear Research Center, recalls a transformative year spent with Hieftje, highlighting not only rigorous work demands but also a sense of community cultivated through social events. This sentiment echoes through the words of Olesik, emphasizing Hieftje’s role in creating a family-like environment that has shaped a lasting community of analytical chemists that continues to this day.

Hieftje’s mentoring legacy is evident in the success of former group members who have gone on to establish their own research groups, emulating the familial culture instilled by their mentor. The collaborative and supportive atmosphere within Hieftje’s group is emphasized by Volker Hoffmann, who experienced a friendly and open environment during his tenure.

Hieftje’s mentoring prowess isn’t limited to research group members; he has also positively impacted chemists globally. Stephen L. Buchwald, a high school student mentored by Hieftje, recalls being introduced to the excitement of science and teamwork, an experience that influenced his career trajectory.

Wise advice and aphorisms characterize Hieftje’s mentorship style. From emphasizing the value of time in the library to encouraging collaboration with other research teams, his guidance has shaped the careers of many. Former students like Lodder and Potyrailo reflect on the enduring impact of Hieftje’s advice on their successful careers.

Hieftje’s mentoring extended beyond his immediate group, with colleagues like Vahid Majidi acknowledging his caring and insightful nature. Farnsworth, who retired recently, attributes much of his career success to Hieftje’s recommendations and support throughout the years.

In addition to mentoring, Hieftje’s positive influence is acknowledged by colleagues and friends. Whether through collaborations with Chris Enke or inspiring competitors like Scott Tanner, Hieftje’s daring work has been a driving force for many.

As Hieftje has formally retired, his enduring legacy is evident in the innovative technologies he developed, the patents he secured, and the generations of analytical chemists he inspired. His impact on the field and the lives of those he mentored will continue to shape the future of analytical chemistry for years to come.

This article was written with the help of artificial intelligence, which was used to summarize previously published material by this author on this subject (1,2). The final manuscript has been carefully edited to ensure accuracy and clarity.

References

(1) Workman, J.; Bush, L. Gary M. Hieftje’s Legacy: Fifty Years of Scientific Contributions. Spectroscopy 2019, 34 (12), 32–44. https://www.spectroscopyonline.com/view/gary-m-hieftje-s-legacy-fifty-years-scientific-contributions (accessed 2023-11-08). This article was republished in 2023 as reference (2).

(2) Workman, J.; Bush, L. Gary M. Hieftje’s Legacy: Fifty Years of Scientific Contributions. Appl. Spectrosc. 2023, 77 (8), 799–812. DOI: 10.1177/00037028231195415 (accessed 2023-11-08).

(3) Hieftje G. M.; Malmstadt, H. V. New Approach to Flame Spectrometric Analysis Utilizing Isolated Droplets of Sample Solution. Anal. Chem. 1969, 41 (13), 1735–1744. DOI: 10.1021/ac60282a022

(4) Peters, D. G.; Hayes, J. M.; Hieftje, G. M. Chemical Separations and Measurements: Theory and Practice of Analytical Chemistry; W. B. Saunders Company, 1974.

(5) Smith Jr, S. B. and Hieftje, G. M. Instrumentation Laboratory Co, 1984. Spectroanalytical System. U.S. Patent 4 462 685, 1984.

(6) Hieftje, G. M. and Shabushnig, J. Indiana University Foundation, 1985. Device for the Accurate Dispensing of Small Volumes of Liquid Samples. U.S. Patent 4 492 322, 1985.

(7) Hieftje, G. M. and Honigs, D. H. Indiana University Foundation, 1987. Method and Device for Spectral Reconstruction. U.S. Patent 4 642 778, 1987.

(8) Hieftje, G. M., Honigs, D. E. and Hirschfeld, T. B. Indiana University Foundation, 1989. Methods and Devices for Near-Infrared Evaluation of Physical Properties of Samples. U.S. Patent 4 800 279, 1989.

(9) Lodder, R. A. Indiana University Foundation, 1989. Sample Holders or Reflectors for Intact Capsules and Tablets and for Liquid Microcells for Use in Near-Infrared Reflectance Spectrophotometers. U.S. Patent 4 882 493, 1989.

(10) Hieftje, G. M. and Wu, M. Indiana University Foundation, 1994. Rotary Spray Chamber Device for Conditioning Aerosols. U.S. Patent 5 335 860, 1994.

(11) Li, G. and Hieftje, G. M. Indiana University Foundation, 1997. Time-of-Flight Mass Spectrometer. U.S. Patent 5 614 711, 1997.

(12) Hieftje, G. M., Ray, S. J., Andrade, F. J., Wetzel, W. C., Webb, M. R., Gamez, G. and Shelley, J. T. Indiana University Research and Technology Corp, 2011. Methods and Apparatus for Ionization and Desorption Using a Glow Discharge. U.S. Patent 7 893 408, 2011.

(13) Webb, M. R., Hieftje, G. M. and Andrade, F. US Department of Energy, 2011. Ambient-Atmosphere Glow Discharge for Determination of Elemental Concentration in Solutions in a High-Throughput or Transient Fashion. U.S. Patent 7 929 138, 2011.

(14) Hieftje, G. M., Andrade, F. J., Ray, S. J. and Shelley, J. T. Indiana University Research and Technology Corp, 2012. Laser Ablation Flowing Atmospheric-Pressure Afterglow for Ambient Mass Spectrometry. U.S. Patent 8 207 494, 2012.

(15) Enke, C. G., Ray, S. J., Graham, A. W., Hieftje, G. M., Dennis, E., Barinaga, C. J. and Koppenaal, D. W. Battelle Memorial Institute Inc, Indiana University Research and Technology Corp, 2013. Method for Enhancement of Mass Resolution Over a Limited Mass Range for Time-of-Flight Spectrometry. U.S. Patent 8 604 423, 2013.

(16) Enke, C. G., Ray, S. J., Graham, A. W., Hieftje, G. M., Barinaga, C. J. and Koppenaal, D. W. Battelle Memorial Institute Inc, Indiana University Research and Technology Corp, 2014. Combined Distance-of-Flight and Time-of-Flight Mass Spectrometer. U.S. Patent 8 648 295, 2014.

(17) Hieftje, G. M., Ray, S. J., Pfeuffer, K. P., Shelley, J. T. and Caldwell, N. J. Indiana University Research and Technology Corp, 2017. Ambient Sampling Mass Spectrometry and Chemometric Analysis for Screening Encapsulated Electronic and Electrical Components for Counterfeits. U.S. Patent 9 607 306, 2017.