Demonstrating Rapid Qualitative Elemental Analyses of Participant-Supplied Objects at a Public Outreach Event

• Published in: Journal of chemical education 2016-10, Vol.93 (10), p.1749-1753
• Main Authors: Schwarz, Gunnar, Burger, Marcel, Guex, Kevin, Gundlach-Graham, Alexander, Käser, Debora, Koch, Joachim, Velicsanyi, Peter, Wu, Chung-Che, Günther, Detlef, Hattendorf, Bodo
• Format: Article
• Language: English
• Subjects: Ablation; Argon; Chemical composition; Chemistry; Coins; Demonstrations (Educational); Foreign Countries; Gas exchange; Gases; Inductively coupled plasma; Instrumentation; Instruments; Laser ablation; Laser beams; Lasers; Mass spectra; Mass spectrometry; Object recognition; Outreach Programs; Qualitative analysis; Qualitative research; Recording; Science Activities; Science Equipment; Science Fairs; Scientific Concepts; Scientific Principles; Spectroscopy; Switzerland
• ISSN: 0021-9584; 1938-1328
• DOI: 10.1021/acs.jchemed.6b00391

A public demonstration of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) for fast and sensitive qualitative elemental analysis of solid everyday objects is described. This demonstration served as a showcase model for modern instrumentation (and for elemental analysis, in particular) to the public. Several steps were made to adapt conventional laboratory-based ICP-MS instrumentation to bring it to the outreach event and also to improve ease-of-use, which helped facilitate discussion with attendees. Rather than the conventional closed-cell design, this setup consisted of a laser ablation (LA) system that allowed for ablation in ambient conditions which enabled swift sample exchange during the demonstration. A gas exchange device was operated between the LA system and the ICP-MS instrument allowing for the replacement of ambient gases with argon. This particular setup was utilized during an open day event to demonstrate how LA-ICPMS can be used for qualitative analysis of major and trace elemental components in objects. In particular, visitors were encouraged to present objects for elemental analysis. Complete elemental analysis of supplied samples such as keys, coins, rings, and necklaces was demonstrated by recording full mass spectra. Variation of the elemental composition across different regions of objects was shown by scanning the laser beam and acquiring transient elemental signals.