The trace race element chemistry of foraminiferal tests reflect the environment in which they grew. Thus geochemical data can be used as paleo-proxies constraining environmental conditions in ancient seas [e.g.: 1]. Seawater chemistry may be influenced by local sources such as hydrothermal activity. However, for elements considered diagnostic for hydrothermalism, reliable experimental data is rare [e.g. 2]. To provide a solid basis for a more complete understanding of trace element partitioning between foraminiferal calcite and seawater, we carried out culture experiments under controlled laboratory conditions. This is the main objective of our study.For our experiment we grew freshly collected benthic foraminifera (Ammonia tepida) in seawater, containing a cocktail of Mn, Co, Ni and Cu, at defined trace element levels.Measurements of the culture solutions were carried out regularly by HR-ICP-MS whereas the calcite of newly grown chambers of the cultured foraminifera was detected by a non-destructive technique - µSy-XRF [3]. To confirm the data LA-ICP-MS measurements have been performed. To distinguish between old and new chambers the calcein labeling technique [4] was applied.First results demonstrate that especially Ni and Cu could be determined with high precission and accuracy using µSy-XRF measurements. We determined trace element/Ca ratios and DNi as well as DCu using LA ICP-MS.