O. Klein, T. Zimmermann, D. Pröfrock

^a Helmholtz-Zentrum Hereon, Institute of Coastal Environmental Chemistry, Max-Planck Str. 1, 21502 Geesthacht, Germany

^b Universität Hamburg, Department of Chemistry, Inorganic and Applied Chemistry, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany

Technologically critical elements (TCEs) play a key role in modern high- technologies. Thus, the investigation of TCEs as potential new, emerging pollutants is a constantly rising field of interest in environmental research. However, u p to now for most TCEs the assessment of potential (eco)toxicological effects on humans and the environment is still hampered by a lack of data. Especially low concentrations of TCEs in environmental matrices (µg kg^-1 or lower) often result in complex and time-consuming sample preparation. The aim of this study is to develop a new multi-element ICP-MS/MS-based approach for the determination of all key TCEs (Sc, Ga, Ge, Nb, In, Te, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Yb, Lu, Ta) in sediments, thus making this approach available to one of the most important matrices for environmental research. Here N₂O is used as a reaction gas, which enables higher oxide formation for many TCEs compared to the frequently used O₂. Thus, improved selectivity and sensitivity can be achieved resulting in LODs between 0.00023 µg L^-1 (Eu) and 0.13 µg L^-1 (Te) for all analyzed TCEs. Additionally for every TCE, except Te, recoveries between 80% and 112% were obtained for at least one of the analyzed reference materials (GBW 07313, GBW 07311, and BCR-2).