2020 Winter Conference on Plasma Spectrochemistry, January 13–18, 2020, Tucson, Arizona

So, what’s next? In a biennial attempt to answer that question the 2020 Winter Conference on Plasma Spectrochemistry continued, in January, to feature growth areas in spectrochemical fundamentals, instrumentation, and applications. Meeting with over 460 participants from 25 countries, the daily program featured novel developments described during 12 symposia, including those dedicated to four sponsored awards by ThermoFisher Scientific, Spectroscopy, and Journal of Analytical Atomic Spectrometry, three topical workshops, and a 3-day poster session. Although many developing techniques have spawned their own special-topic meetings (e.g., LIBS, immunology, environmental forensics, food authentication, nanomaterial analysis) during 2019, the Winter Conference continued to integrate topics and attract approximately 300 oral and poster contributors, while 36 invited, 7 plenary, and 4 heritage lectures, offered by senior scientists, punctuated the 6-day program [Tables 1 and 2].

Table 1 Heritage lectures

HL01 (From there to here), to another there and back again, Scott D. Tanner, Canada

HL02 From pyramids to plasmas – the heritage of analytical chemistry in Africa, Rob McCrindle, South Africa

HL03 Open box before eating pizza – a relevant perspective! Richard E. Russo, California

HL04 Mirabile dictu: isotope measurements as a truth serum, Michael E. Ketterer, Arizona

HL05 Being lucky, Gary Hieftje, Indiana

Table 2 Plenary and award lectures

a Thermo Fisher Scientific 2020 Winter Conference Award in Plasma Spectroscopy. b JAAS Emerging Investigator Lectureship 2019 Award. c Spectroscopy’s 2020 Emerging Leader in Atomic Spectroscopy Award. d Thermo Fisher Scientific 2020 Young Plasma Scientists Award in Plasma Spectroscopy.

PL01 From there to here, (to another there and back again), Scott D. Tanner^a, Toronto, Canada

PL02 Massively multiplexed single cell analysis in human health goes elemental, Sean Bendall, Stanford University School of Medicine, Palo Alto, California

PL03 High-precision isotopic analysis for clinical advances, Marta Costas Rodriguez^b, et al., Ghent University, Ghent, Belgium

PL04 Challenges in environmental chemistry: ICP-MS is only one of many techniques to describe environmental and biological processes, Jörg Feldmann, Eva M. Krupp, University of Aberdeen, Aberdeen, Scotland, United Kingdom

PL05 Finding the big picture in the pixels, Jacob T. Shelley^c, et al., Rensselear Polytechnic Institute, Troy, New York

PL06 Emerging ultrafast laser sampling approaches in laser plasma spectrochemistry, Vassilia Zorba, et al., Lawrence Berkeley National Laboratory, Berkeley, California

PL07 Challenges in aerosol generation and transport for atomic spectrometry, José-Luís Todolí, University of Alicante, Alicante, Spain

IL15 Surveying the three dimensional elemental landscape of solid sample surfaces with glow discharge spectroscopy, Gerardo Gamez^d, et al., Texas Tech University, Lubbock, Texas

Arranged by Norbert Jakubowski, the conference began with a full day on bioimaging, mass cytometry, and laser imaging mass spectrometry fundamentals and applications. The contributions of mass cytometry, based on ICP-TOF MS, to the biomedical field appear to be little recognized by the atomic spectrochemical community, although the technique and instrumentation has had a significant impact in immunology. Lectures by co-developer Scott Tanner described the imaginative spirit behind the progress and commercialization of mass cytometry (Table 1). Furthermore, both inorganic and organic imaging generally based on laser ablation sampling have made major strides.

According to Sean Bendall, Stanford University School of Medicine, US, the novel combination of elemental mass spectrometry with single cell analysis (mass cytometry) and imaging (multiplexed ion beam imaging; imaging mass cytometry) offers routine examination of 30–50 parameters with heavy metal isotopes as reporters, and enables us to reach new levels of hematopoietic immune organization, detailed hematopoietic immune function and dysfunction, identifying new cell populations, regulatory relationships and clinically predictive features underlying disease, which provides an opportunity to evaluate diseases and pharmacological therapeutics as specific perturbations to the inherent human cellular order. Bernd Bodenmiller, University of Zürich, envisioned that imaging mass cytometry would enable a systems biology approach to understand and diagnose disease and to guide treatment.

Elemental speciation, metallomics, and single cell diagnostics, utilizing coupled methods for species identification and quantification, continued to develop, and representative contributions catalogued the progress. María Montes-Bayón, University of Oviedo, Spain, felt that elemental analysis in single cells was an important milestone for metallomics and a field of increasing interest. According to X. Chris Le, University of Alberta, arsenic speciation analysis, using HPLC-ICP-MS/ESI-MS, was critical to understanding risk factors in the development of arsenic-induced diseases.

Laser ablation and laser-induced breakdown spectroscopy (LIBS) provide practical application areas in many fields, and a full day of lectures and posters emphasized their impact.

Three workshops highlighted new instrumentation, biological and clinic methodologies, and methods for stable isotope and forensic materials. Development of novel applications in many fields, including environmental chemistry, food science, geochemistry, marine science, and especially high precision isotope analyses are driven by new capabilities, especially with high resolution and multiple series analyzers (MSⁿ) in mass spectrometry. Although discussed as a research tool, ultimate high-resolution mass spectrometry based on trap configurations is yet to become commercial. Mikhail Belov, et al., Thermo Fisher Scientific, believed that their novel elemental imaging platform based on an ICP interfaced Orbitrap™ mass analyzer developed for high-speed, high-spatial and mass resolution, and high-mass-accuracy multi-elemental imaging was poised to become an important analytical tool for practical biomedical applications. Frank Vanhaecke, Ghent University, Belgium, observed that high-precision isotopic analysis of essential mineral elements using MC-ICP-MS was finding its place as a useful technique in a biomedical/clinical environment because some diseases cause measurable systematic changes in the isotopic composition of such elements (e.g., Mg, Fe, Cu, Zn) in biofluids. The potential of using enriched spikes of naturally occurring non-radioactive isotopes (e.g., ²⁶Mg, ⁸⁴Sr, ⁸⁶Sr) as monitors in life sciences has not yet been fully exploited with ICP sources, noted Johanna Irrgeher, Montanuniversität Leoben, Austria, although they allow monitoring of elemental uptake, distribution, deposition or mobilization in living organisms and to study the fate of materials applied for medical purposes. Furthermore, according to Michael Ketterer, the ICP-MS technique has had enormous impact on shaping the use of isotope measurements in a wide range of scientific endeavors such as in environmental isotope geochemistry, as studies of human impacts of the recent past upon global geochemical processes has demonstrated.

Plasma discharges based on atmospheric pressure glow discharges, for example, attack novel inorganic and organic analyses not possible with conventional ICP systems. Tyler Williams and R. Kenneth Marcus, Clemson University, emphasized that the liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma was a true, combined atomic and molecular (CAM) ionization source with ability to interface with transportable MS systems that have atmospheric pressure interfaces to provide molecular capabilities, in terms of sensitivity, a range of analyte types, and high matrix tolerance, beyond those of the standard electrospray ionization (ESI) source.

Driven by the need to measure nanoparticles and microplastics in the environment, ICP-MS techniques based on single particle analysis continue to grow. Petra Krystek, Vrije Universiteit, the Netherlands, observed that environmental sciences deliver challenging topics for analytical method development, sampling and sample pre-treatment. While gaseous and small particles were of great relevance, nanomaterial analysis of process materials, consumer products, food and medicine require interdisciplinary and new analytical approaches to cover forthcoming questions resulting from an increased use of engineered nanomaterials.

Finally, novel sample introduction devices and techniques were reported in a symposium arranged by Akbar Montaser, and speakers featured sample introduction approaches especially from an engineering perspective. For example, José-Luis Todolí, University of Alicante, Spain, gave directions and recommendations related to the optimization of the sample introduction step for ICP-OES and ICP-MS. Although an effort exists to minimize sample preparation, it also continues as the backbone of many plasma spectrochemical measurements, for example, Mario Corte-Rodríguez et al. discussed sample preparation of cancer cells for single cell analysis by ICP-MS. They studied the suitability of fixation methods with several cisplatin-treated cell cultures and tested bulk and single cell analysis of Pt content using SC-ICP-TOF-MS. To streamline workflow and to improve productivity, instrument manufacturers introduced commercially available, often automated, sample preparation systems. For example, Morgan J. Nail et al., Centers for Disease Control and Prevention, reduced sample preparation time and human error in their lot-testing program using a commercial, automated device.

Practical education was not overlooked when the conference provided 35 pre-conference short educational development courses taught by many of the same scientists who gave invited lectures. These courses have been popular and continued to attract academic and industrial participants. Some of the 36 exhibitors (Agilent Technologies, Thermo Fisher Scientific) sponsored luncheon technical seminars as well.

So what’s next is defined by plasma techniques that push analysis characteristics including sensitivity, matrix and interference freedom, and high precision; original developments like mass cytometry and single-particle ICP-MS; and new commercial instrumentation, such as high resolution triple quad mass analyzers and coupled separation and measurement instruments, that keep the field alive and moving to resolve difficult sample analyses and open new analysis possibilities. Although disrupted by the appearance of the corona virus in March 2020, the field of plasma spectrochemistry will continue to grow after the pandemic passes and atomic and mass spectrosopists return to their laboratories and again convene at local and international meetings. The next Winter Conference in North America will probably meet in early 2022, while the Asia-Pacific and European Winter Conferences will resume in 2021 or 2023.

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