Novel sampling techniques for trace element quantification in ancient copper artifacts using laser ablation inductively coupled plasma mass spectrometry Marcel Burger a , Reto Glaus a , Vera Hubert b , Samuel van Willigen b , Marie W € orle-Soares b , Fabien Convertini c , Philippe Lefranc d , Ebbe Nielsen e , Detlef Günther a, * a ETH Zürich, Laboratory of Inorganic Chemistry, Wolfgang-Pauli-Strasse 10, 8093 Zürich, Switzerland b Swiss National Museum, Sammlungszentrum, 8910 Affoltern am Albis, Switzerland c Institut National de Recherches Arch eologiques Pr eventives and UMR 7269-LAMPEA, 561 rue Etienne Lenoir, 30900 Nîmes, France d Institut National de Recherches Arch eologiques Pr eventives and UMR 7044, Centre arch eologique de Strasbourg, 10 rue d’Altkirch, 67000 Strasbourg, France e Kanton Luzern Arch€ aologie, Libellenrain 15, 6002 Luzern, Switzerland article info Article history: Received 10 December 2015 Received in revised form 25 April 2017 Accepted 29 April 2017 Keywords: Early copper metallurgy Neolithic copper artifacts Portable laser ablation sampling Laser ablation inductively coupled plasma mass spectrometry abstract Elemental analyses using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) have great potential in archaeometric research due to the quasi-nondestructive sampling and excellent sensitivity of the method. However, the application of LA-ICPMS in cultural heritage research is often limited because samples are too large to fit within an ablation cell or cannot be moved to the laboratory. This work reports the development of analytical routines that allow trace element quantification in ancient copper artifacts regardless their mobility, size or geometry. In this study, the LA sampling step was performed in ambient air using a portable laser ablation device (pLA). The LA module was placed on the object of interest and the laser-generated aerosol was either directly transferred into the ICPMS via a large-capacity gas exchange device (GED) or collected on pol- ycarbonate membrane filters, which were later analyzed by LA-ICPMS. The analytical performances of both approaches were assessed using various copper reference materials. The laboratory-based, ablation- cell-independent pLA-GED-ICPMS method, yielded accuracies comparable to those obtained via con- ventional LA-ICPMS (±10%). Good performances (±30%) were also obtained with the pLA þ filter sam- pling approach and subsequent LA-ICPMS analysis. Limits of detection for both approaches were in the low mg/g or sub- mg/g range, making these methods interesting for trace element analysis. After validating these laser-based techniques on an ancient copper object whose elemental compo- sition had previously been determined by graphite furnace atomic absorption spectroscopy (GFAAS), five Neolithic copper artifacts found in Switzerland and France were analyzed using the pLA þ filter sampling approach. A copper dagger found in Lattrigen, Switzerland was analyzed using the pLA-GED-ICPMS method. Furthermore, the laser-induced sample damage was investigated. The trace element profiles of the objects under investigation were compared to those of well- characterized copper artifacts. Thus, the chronological and cultural background of these artifacts could be determined. One group of copper artifacts showed high arsenic concentrations (up to 1% [w/w]) and could be attributed to “Mondsee copper”, which was particularly common in the eastern Alps during the Middle European Late Neolithic. Other objects under investigation showed trace element concentrations, which are typical for the Late Neolithic north of the Alps. One artifact had a composition typical for objects from the Late Neolithic of Southern France. © 2017 Published by Elsevier Ltd. 1. Introduction Laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) is a versatile and powerful technique for elemental * Corresponding author. E-mail address: guenther@inorg.chem.ethz.ch (D. Günther). Contents lists available at ScienceDirect Journal of Archaeological Science journal homepage: http://www.elsevier.com/locate/jas http://dx.doi.org/10.1016/j.jas.2017.04.009 0305-4403/© 2017 Published by Elsevier Ltd. Journal of Archaeological Science 82 (2017) 62e71