Total reflection X-ray fluorescence (TXRF) instrument

本申请是用于同时分析超痕量范围内从镁到铀金属的全反射x射线荧光（TXRF）仪器。该仪器应能够分析生物（薄片）和水样品以及固体。这一需求概况反映了“应用水生毒理学”应用工作组的广泛定位，其研究重点一方面包括稀土金属生态毒性的基本问题。研究目标是建立镧和钆的生物配体模型，并研究镧系元素对生物模型群落的影响。另一方面，应用研究课题包括制订一套系统，对不同河流和沿海地区的沉积物质量进行生态毒理学评估，以及研制一种生物传感器，用于探测波罗的海倾倒的化学战剂。所有主题都是通过关注生物可利用污染物对生物体的影响的方法来统一的，使用微生物、藻类、线虫、水蚤和鱼卵作为测试生物体。考虑到在测试系统中使用活生物体的自然变异性，从实验装置中定期抽取的小体积样品中进行多元素分析对于研究污染物-生物群相互作用是必要的。因此，高样品通量、高灵敏度和低成本是应用系统的要求之一。通过使用两种激励系统（钼和钨），即使是环境相关的污染物，否则难以确定，如镉，锡和锑，也可以在ppb范围内测量。初步测量证实，对镧和钆等镧系元素的灵敏度在较低的ppb范围内。在组织制剂的帮助下，测定生物体内的生物积累是可能的。购买该设备是为了取代现有的旧设备，以便将来在教学中使用。

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.