EMSL: David W Koppenaal's Publications

Schilling GD, JT Shelley, JAC Broekaert, RP Sperline, MB Denton, CJ Barinaga, DW Koppenaal, and GM Hieftje. 2009. "Use of an ambient ionization flowing atmospheric-pressure afterglow source for elemental analysis through hydride generation." Journal of Analytical Atomic Spectrometry 24(1):34-40. Abstract An ambient mass spectrometry ionization source based on an atmospheric-pressure flowing afterglow has been coupled to a Mattauch-Herzog mass spectrograph capable of simultaneous acquisition of a range of mass-to-charge values by means of a Faraday-strip array detector. The flowing afterglow was used as the ionization pathway for species produced by hydride generation. This ionization strategy circumvents problems, such as discharge instabilities or memory effects, induced by introducing the gaseous sample into the discharge. The generated spectra show both atomic and molecular peaks; calibration curves were calculated for both peak types with limits of detection for arsenic below 10 ppb. This study demonstrates the ability to use an ambient mass spectrometry source, commonly used for molecular analyses, for the detection of gas phase elemental species with the possibilty of performing speciation by coupling with a separation technique.

Koppenaal DW, and GM Hieftje. 2007. " Metallomics – The Future of Atomic Spectroscopy? ." Journal of Analytical Atomic Spectrometry 22(2):111. doi:10.1039/b618394h Abstract Metallomics is defined as the study of metals and metal species, and their interactions, transformations, and functions in biological systems. The full complement of metals and metal moieties (free and bound) is accordingly known as the metallome. The terms are relatively new ones, first coined by R.J.P. Williams of Oxford University and Hiroki Haraguchi of Nagoya University early in the present millennium. Metallomics is a new moniker for the field of bioinorganic chemistry, extending and broadening that discipline much as genomics has done for genetics, and is appositely harmonious with other ‘ohmics’ terms like genomics, proteomics, and metabolomics. Metallomics is also distinguished from other terms (e.g. speciation) by consideration of the global role of all metals/metalloids in a system.

Koppenaal DW, and GM Hieftje. 2007. "Metallomics - An Interdisciplinary and Evolving Field." Journal of Analytical Atomic Spectrometry 22(8):855. doi:10.1039/b710205b Abstract In an editorial earlier this year (JAAS, 22, 111, 2007), we opined that metallomics, the study of metals in biological systems, would be an increasingly important topic in elemental analysis in general and for this journal in particular . This issue of the journal, co-edited by the two of us, is a second special issue covering the subject of Metallomics (the first issue was JAAS, 19/1, 2004). The present issue is comprised of technique, application, and perspective papers that address this emerging field of study and show how atomic spectrometry is contributing to the understanding of biological systems. The subjects covered range from metal binding in plants through investigations of metal and metalloids in samples of biological fluids to the study of food supplements and drug interactions in cells. The issue includes two Critical Reviews. Yuxi Gao and colleagues discuss advanced nuclear analytical techniques for the emerging field of metalloproteomics. While Laura Liermann and her colleagues consider how micro-organisms extract metals from minerals in the environment for utilization in metabolic processes. The content of some of these papers stretches the traditional boundaries and scope of this journal, as echoed by the reviewers of some of the papers. This discussion about scope requires perhaps further debate. However, it is our view that while the Journal must remain true to its core aims, it must also strive to accommodate and motivate a wider authorship and readership. Metallomics is a field that transcends biology and microbiology, biochemistry, clinical chemistry, environmental chemistry, geochemistry, and yes, atomic spectroscopy. If JAAS aspires to be a leading force in metallomics, the Journal must expand its horizons beyond traditional analytical spectroscopy per se. Accordingly, in this special issue you will find papers that have a heavy clinical emphasis, which speak to complementary (non-atomic) spectroscopic techniques, and that provide perspectives that only touch on the use of atomic spectroscopy. The field of metallomics is still in the process of being defined and we hope to inform that definition by including the widest body of technical literature on the subject. We hope that you will find these contributions to be informative, inspiring, and enlightening and consider submitting your own research in this area to JAAS.

Koropatkin N, DW Koppenaal, HB Pakrasi, and TJ Smith. 2007. "The Structure of a Cyanobacterial Bicarbonate Transport Protein, CmpA." Journal of Biological Chemistry 282(4):2606-2614. doi:10.1074/jbc.M610222200 Abstract Cyanobacteria, blue-green algae, are the most abundant autotrophs in aquatic environments and form the base of the food chain by fixing carbon and nitrogen into cellular biomass. To compensate for the low selectivity of Rubisco for CO₂ over O₂, Cyanobacteria have developed highly efficient CO₂concentrating machinery of which the ABC transport system CmpABCD from Synechocystis PCC 6803 is one component. Here we describe the structure of the bicarbonate binding protein, CmpA, in the absence and presence of bicarbonate and carbonic acid. CmpA is highly homologous to the nitrate transport protein, NrtA. CmpA binds carbonic acid at the entrance to the ligand-binding pocket whereas bicarbonate binds in nearly an identical location compared to nitrate binding to NrtA. Unexpectedly, bicarbonate binding is accompanied by a metal ion, identified as Ca²⁺ via inductively coupled plasma optical emission spectrometry. The binding of bicarbonate and metal is highly cooperative and suggests that CmpA co-transports bicarbonate and calcium.

Schilling GD, FJ Andrade, JH Barnes IV., RP Sperline, MB Denton, CJ Barinaga, DW Koppenaal, and GM Hieftje. 2007. "Continuous Simultaneous Detection in Mass Spectrometry." Analytical Chemistry 79(20):7662-7668. doi:10.1021/ac070785s Abstract In mass spectrometry, several advantages can be derived when multiple mass-to-charge values are detected simultaneously. One such advantage is an improved duty cycle, which leads to superior limits of detection, better precision, shorter analysis times, and reduced sample sizes. A second advantage is the ability to reduce correlated noise by taking the ratio of two or more simultaneously collected signals, enabling greatly enhanced isotope ratio data. A final advantage is the elimination of spectral skew, leading to more accurate transient signal analysis. Here, these advantages are demonstrated by means of a novel Faraday-strip array detector coupled to a Mattauch-Herzog mass spectrograph. The same system is used to monitor elemental fractionation phenomena in laser ablation inductively coupled plasma mass spectrometry.

Koppenaal DW. 2006. "JAAS - 20 Years of Manuscripts, Citations, and Scientific Impact ." Journal of Analytical Atomic Spectrometry 21(3):259-262. doi:10.1039/b601801g Abstract David W. Koppenaal is a Laboratory Fellow, and Associate Director of the Biological Sciences Division at Pacific Northwest National Laboratory. He has been a member of the JAAS Editorial Board since 2000. Dr. Koppenaal first published in JAAS in 1988, and was recently guest editor for a 2004 special issue on Collision & Reaction Cells in Atomic Mass Spectrometry. He is currently also arranging a special issue on Metallomics for early 2007 publication. Dr. Koppenaal’s research interests include atomic mass spectrometry instrumentation and applications, with special interests in interference reduction using collision/reaction cells, high-resolution MS techniques using ion traps, new generation MS detectors, and radionuclear and metallomic applications of ICPMS.

Peschel BU, FJ Andrade, WC Wetzel, GD Schilling, GM Hieftje, JAC Broekaert, R Sperline, MB Denton, CJ Barinaga, and DW Koppenaal. 2006. "Electrothermal vaporization coupled with inductively coupled plasma array-detector mass spectrometry for the multielement analysis of Al2O3 ceramic powders." Spectrochimica Acta. Part B, Atomic Spectroscopy 61(1):42-49. Abstract An electrothermal vaporization (ETV) system useful for the analysis of solutions and slurries has been coupled with a sector-field inductively coupled plasma mass spectrometer (ICP-MS) equipped with an array detector. The ability of this instrument to record the transient signals produced in ETV-ICP-MS is demonstrated. Detection limits for Mn, Fe, Co, Ni, Cu, Zn and Ga are in the range of 4-60 pg µL-1 for aqueous solutions and in the low µg g-1 range for the analysis of 10 mg mL-1 slurries of Al2O3 powders. The dynamic ranges measured for Fe, Cu and Ga spanned 3-5 orders of magnitude when the detector was operated in the low-gain mode and appear to be limited by the ETV system. Trace amounts of Fe, Cu and Ga could be directly determined in Al2O3 powders at the 2-270 µg g-1 level without the use of thermochemical reagents. The results well agree with literature values for Fe, whereas deviations of 30-50% at the 2-90 µg g-1 level for Cu and Ga were found.

Schilling GD, FJ Andrade, JH Barnes, RP Sperline, MB Denton, CJ Barinaga, DW Koppenaal, and GM Hieftje. 2006. "Characterization of a Second-generation Focal-plane Camera Coupled to an Inductively Coupled Plasma Mattauch-Herzog Geometry Mass Spectrograph." Analytical Chemistry 78(13):4319-4325. Abstract A second-generation Faraday-strip array detector has been coupled to an inductively coupled plasma Mattauch- Herzog geometry mass spectrograph, thereby offering simultaneous acquisition of a range of mass-to-charge ratios. The second-generation device incorporates narrower, more closely spaced collectors than the earlier system. Furthermore, the new camera can acquire signal on all collectors at a frequency greater than 2 kHz and has the ability to independently adjust the gain level of each collector. Each collector can also be reset independently. With these improvements, limits of detection in the hundreds of picograms per liter for metals in solution have been obtained. Some additional features, such as a broader linear dynamic range (over 7 orders of magnitude), greater resolving power (up to 600), and improved isotope ratio accuracy were attained. In addition, isotope ratio precision as low as 0.018% RSD was achieved.

Koppenaal DW, CJ Barinaga, MBB Denton, RP Sperline, GM Hieftje, GD Schilling, FJ Andrade, and JH Barnes IV.. 2005. "MS Detectors." Analytical Chemistry 77(21):418A-427A. Abstract Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

Sperline RP, AK Knight, CA Gresham, DW Koppenaal, GM Hieftje, and MBB Denton. 2005. "Read-Noise Characterization of Focal Plane Array Detectors via Mean-Variance Analysis." Applied Spectroscopy 59(11):1315-1323. Abstract Mean-variance analysis is described as a method for characterization of the read-noise and gain of Focal Plane Array (FPA) detectors, including CCDs, CIDs, and CMOS multiplexers (IR arrays). Practical FPA detector characterization is outlined. The non-destructive readout capability available in some FPA devices is discussed as a means for signal-to-noise ratio improvement. Derivations of the equations are fully presented to unify understanding of this method by the spectroscopic community.