Towards ultra-trace element measurements in organic-rich samples: tracing past and modern environmental changes

地球的环境在不断变化。环境变化的原因和后果是复杂的，代表了一个重要的研究前沿，如果克服，可以产生重大的学术和社会影响。然而，我们的能力，研究他们目前受到限制，我们的能力，以衡量一系列的关键地球化学示踪剂的环境档案使用国家的最先进的技术。我们的目标是通过建立一个超痕量元素测量设施，在分析环境地球化学方面迈出新的一步，该设施专门用于对追踪过去和现在环境变化的样本进行调查，以了解i）地球如何变得适合居住; ii）人类活动如何影响气候，海洋，土壤和地下水; iii）关键金属的指纹来源，以实现绿色经济。目前的局限性围绕着环境档案的挑战性方面，这些档案通常富含难以消化的有机材料，以及关键的非地球化学示踪剂的丰度非常低并且受到质谱仪中有害干扰的影响。我们将通过建立微波消解三重四极杆ICP-MS设备（MD-Qubed）来解决这些问题，该设备专门用于测量富含有机物的样品中具有技术挑战性的微量元素的极低丰度。通过量化整个周期表中环境档案中超低水平存在的关键地球化学示踪剂的循环，这种独特的分析设施将使开创性的研究能够解决与地球过去，现在和未来环境变化有关的一级挑战。事实上，如果像磷酸盐和硝酸盐这样的化合物是生命的关键营养素，那么像铀或砷这样的化合物则是有毒的。确定从海洋中沉淀下来的富含有机物的沉积物中这种地球化学示踪物的丰度可以作为过去海洋化学的指纹。例如，这些样本中的磷酸盐水平可以说明过去海洋中的营养限制，并有助于破译对生命进化的控制。其他元素，如铀、硒和钼，在同一沉积物中，或硼和锂在海洋碳酸盐档案中（例如，有孔虫，珊瑚），可以分别告诉海洋和大气中的氧和碳水平。同样，我们的目标是了解有毒元素（如铀，砷，镉，钴等）的分布和流动性。水、土壤和沉积物中的生物多样性及其对现代生命形式的影响。因此，研究地质和现代样品中的元素对于追踪过去和现代环境变化至关重要。我们的设施的一个关键目标也将是开发方法来追踪与采矿和工业活动有关的人为污染，以及关键金属的来源，以实现更绿色的未来。MD-Qubed设施的检测限提高后，将能够追踪土壤中的硒和碲等关键微量金属，这些元素是向绿色技术革命过渡所必需的。我们还将利用这项技术来追踪放射性核素（例如，铀、钚.）在样品和海洋生物中检测潜在的毒性和在地球系统中的流动性。这些研究将致力于调整可行的采矿方法和污染补救措施的潜力，以实现更绿色的可持续的未来环境。最后，在威尔士和英国西南部建立这样一个独特的设施将有利于对区域和国家环境变化感兴趣的大量研究团体。它还将补充新成立的卡迪夫地球微量元素和同位素化学实验室（CELTIC），并在该地区建立一个新的尖端分析设施。

Earth's environment is everchanging. The causes and consequences of environmental changes are complex and represent a significant research frontier from which significant academic and societal impact can be derived if overcome. However, our capacity to study them are currently limited by our ability to measure a range of key biogeochemical tracers in environmental archives using state-of-art techniques. We aim to take a new step in analytical environmental geochemistry by setting up an ultra-trace element measurement facility specifically designed to interogate samples tracing past and present environmental change to understand i) how the Earth became habitable; ii) how anthropogenic activity affects climate, oceans, soils and groundwater and; iii) fingerprint sources of critical metals for a greener economy. Current limitations hinge around the challenging aspect of environmental archives which are typically rich in organic material difficult to digest, and the fact that key biogeochemical tracers are both in very low-abundance and affected by detrimental interferences in mass spectrometers. We will remedy these issues by setting up Microwave Digestion triple quadrupole ICP-MS facility (MD-Qubed) specifically designed to measure very low-abundance of technically challenging trace-elements in organic-rich samples. By allowing the quantification of the cycling of key biogeochemical tracers present in ultra-low level in environmental archives across the entire periodic table, this unique analytical facility will enable groundbreaking studies to tackle first order challenges pertaining to Earth's past, present and future environmental changes. Indeed, if some compounds like phosphate and nitrate are critical nutrients for life, others like uranium or arsenic are poisonous. Determination of the abundance of such geochemical tracers in organic-rich sediments precipitated from the oceans can act as fingerprints of past ocean chemistry. For instance, phosphate-levels in these samples can inform about nutrient limitation in past oceans and help decipher controls on the evolution of life. Other elements, like uranium, selenium and molybdenum, in the same sediments, or boron and lithium in marine carbonate archives (e.g., foraminifera, corals), may respectively tell about oxygen and carbon level of the oceans and atmosphere. Similarly, we aim to understand the distribution and mobility of anthropogenically-derived poisonous elements (e.g: uranium, arsenic, cadmium, cobalt...) in water, soils and sediments, and their impact on modern life-forms. Thus, studying elements in geological and modern samples is critical for tracing both past and modern environmental changes. A key aim of our facility will also be to develop methods to trace anthropogenic pollution related to mining and industrial activities but also sources of critical metals for a greener future. The improved detection limits of the MD-Qubed facility will allow tracing of key trace metals such selenium and tellurium in soils, elements that are necessary for a transition towards the green technology revolution. We will also take advantage of this technology to trace radionuclides (e.g., uranium, plutonium,...) in samples and marine organisms to examine potential toxicity and mobility through the Earth System. Such studies will work towards adapting viable mining approaches and the potential for pollution remedies for a greener sustainable future environment.Finally, setting up such a unique facility in Wales and the South West of the UK will benefit a large range of research groups interested in environmental changes, both regionally and nationally. It will also complement the newly set-up Cardiff Earth Laboratory for Trace Element and Isotope Chemistry (CELTIC) and doing so establish a new cutting-edge analytical facility in this region.