Chemical-vapor generation of transition metals through the reaction with tetrahydroborate in recent achievements in analytical atomic spectrometry Pawel Pohl *, Piotr Jamroz, Maja Welna, Anna Szymczycha-Madeja, Krzysztof Greda Analytical Chemistry Division, Faculty of Chemistry, Wroclaw University of Technology, Wybrzeze Stanislawa Wyspianskiego 27, Wroclaw 50-370, Poland ARTICLE INFO Keywords: Analysis Analytical figure of merit Analytical performance Atomic spectrometry Chemical-vapor generation Reaction efficiency Reaction enhancer Tetrahydroborate Transition metal Volatile species ABSTRACT We overview the literature available in the past 10 years relevant to chemical-vapor generation (CVG) of transition metals in analytical atomic spectrometry. We focus attention on chemical and physical pa- rameters facilitating reaction efficiency, and other experimental conditions affecting efficient separa- tion and transportation of the volatile species generated. We discuss the overall efficiency of the process and the susceptibility to interferences in the liquid and gaseous phases with respect to the two-step mech- anism of the generation of volatile species and the chemical nature of analyte vapors. We highlight the role of reaction enhancers, such as complexing reagents, surfactants, dispersed metals and ionic liquids. Finally, we give examples of analytical figures of merit and analytical applications of CVG with different methods of atomic spectrometry. © 2014 Elsevier B.V. All rights reserved. Contents 1. Introduction ........................................................................................................................................................................................................................................................ 144 2. Reaction and separation systems for chemical-vapor generation .................................................................................................................................................... 145 2.1. Flow-injection manifolds .................................................................................................................................................................................................................. 145 2.2. Continuous-flow manifolds .............................................................................................................................................................................................................. 146 3. Reaction, separation and transport conditions ....................................................................................................................................................................................... 147 4. Evidence and efficiency of chemical-vapor generation ........................................................................................................................................................................ 149 5. Role of auxiliary substances .......................................................................................................................................................................................................................... 150 6. Interferences ....................................................................................................................................................................................................................................................... 151 7. Analytical applications and performance ................................................................................................................................................................................................. 152 8. Conclusions ......................................................................................................................................................................................................................................................... 154 Acknowledgements .......................................................................................................................................................................................................................................... 154 References ............................................................................................................................................................................................................................................................ 154 1. Introduction When Sturgeon and his co-workers [1] reported in 1996 a suc- cessful generation of volatile species of Cu in the reaction with NaBH4 in the medium of HCl and their further detection by inductively- coupled plasma optical emission spectrometry (ICP-OES), they could not have expected that, during the next 10 years, the scope and the aim of hydride generation (HG) would enormously and unexpectedly expand to a number of transition metals from groups 3 to 12 of the Periodic Table, including noble metals [2–10]. Since then, a tremendous effort has been made to provide experimental conditions for stable chemical-vapor generation (CVG) of volatile species of these metals, increase the overall efficiency of the process, propose the mechanism of the CVG reaction, evaluate the chemi- cal nature of vapor-reaction products and successfully apply this new sample-introduction technique to trace-element analysis of rele- vant environment samples. As shown in the research done in the past decade, since the first review on this topic was released in 2004 [11], three development milestones made in CVG deserve special attention, i.e.: * Corresponding author. Tel.: +48 71 320 3445; Fax: +48 71 320 2494. E-mail address: pawel.pohl@pwr.wroc.pl (P. Pohl). http://dx.doi.org/10.1016/j.trac.2014.04.010 0165-9936/© 2014 Elsevier B.V. All rights reserved. Trends in Analytical Chemistry 59 (2014) 144–155 Contents lists available at ScienceDirect Trends in Analytical Chemistry journal homepage: www.elsevier.com/locate/trac