Total reflection X-ray fluorescence (TXRF) instrument

该应用程序是一个全反射X射线荧光（TXRF）仪器，用于同时分析从镁到铀的超痕量金属。该仪器应能够分析生物（薄切片）和水样品以及固体。这一要求反映了申请工作组“应用水生毒理学”的广泛方向，其研究重点一方面包括稀土金属生态毒性的基本问题。研究目标是镧和钆的生物配体模型的发展，以及镧系元素对生物模型群落的影响的调查。另一方面，应用研究课题包括：制定一个对不同河流和沿海地区沉积物质量进行生态毒理学评估的系统，以及开发一种生物传感器，用于探测在波罗的海倾倒的化学战剂。所有的主题是统一的方法，重点是生物可利用的污染物对生物体的影响，使用微生物，藻类，线虫，水蚤和鱼卵作为测试生物。考虑到与在试验系统中使用活生物体有关的自然变异性，有必要对从实验装置中定期抽取的小体积样品进行多元素分析，以调查污染物-生物群的相互作用。因此，具有高灵敏度和低成本的高样品通量是所应用系统的要求之一。通过使用两个激发系统（钼和钨），即使是环境相关的污染物，如镉，锡和锑，也可以在ppb范围内测量。镧系元素，如镧和钆的灵敏度是在较低的ppb范围内，初步测量证实。使用所申请的系统，可以借助组织学标本等手段确定生物体内的生物累积性。购买该设备的目的是取代现有的旧设备，然后在未来的教学中使用。

This application is for a total reflection X-ray fluorescence (TXRF) instrument for the simultaneous analysis of metals from magnesium to uranium in the ultratrace range. The instrument should be able to analyze biological (thin sections) and aqueous samples as well as solids. This requirement profile reflects the broad orientation of the applying working group "applied aquatic toxicology", whose research focus on the one hand includes fundamental questions on the ecotoxicity of rare earth metals. Research goals are the development of a biotic ligand model for lanthanum and gadolinium, and the investigation of the effects of lanthanides on biological model communities. On the other hand, applied research topics include the elaboration of a system for ecotoxicological assessment of sediment quality of different rivers and coastal areas, and the development of a biological sensor for the detection of dumped chemical warfare agents in the Baltic Sea. All topics are united by the approach of focusing on the effect of bioavailable pollutants on organisms, using microorganisms, algae, nematodes, daphnia, and fish eggs as test organisms. Multielement analyses in small-volume samples drawn periodically from experimental set-ups are necessary to investigate contaminant-biota interactions, taking into account the natural variability associated with the use of living organisms in test systems. High sample throughput with high sensitivity and low cost are thus among the requirements for the system applied for. By using two excitation systems (molybdenum and tungsten), even environmentally relevant pollutants that are otherwise difficult to determine, such as cadmium, tin and antimony, can be measured in the ppb range. The sensitivity for lanthanides such as lanthanum and gadolinium is in the lower ppb range, as confirmed by preliminary measurements. The determination of bioaccumulation in organisms, among other things with the help of histological preparations, is possible with the system applied for. The acquisition of this device is intended to replace an older, existing device, which will then be used in teaching in the future.