Critical addition of microwave digestion capabilities to ICP-MS facility

硒（Se）和汞（Hg）是在水生食物链中生物积累和放大的最重要的微量元素，对加拿大各地，特别是在某些类型的工业作业附近的食肉水禽和鱼类以及食用它们的人口构成潜在的健康风险。稀土元素（ree）在许多半导体和电子应用中具有越来越重要的技术意义，并且通过垃圾填埋场渗滤液和采矿活动越来越多地进入环境，这就需要（生态）毒理学研究来确定稀土元素是否对水生生物或人类构成风险。有证据表明，在所有这些过程中，硒、汞和稀土通常与不溶性颗粒或胶体（=不能通过过滤去除的小颗粒）有关，但目前没有足够的分析方法来量化水中颗粒或胶体汞、硒或稀土的浓度。有了申请的资金，我们将在威尔弗里德劳里埃大学（WLU）建立一个样品制备实验室，在该实验室中，水样通过微波消解预处理，以精确量化颗粒或胶体汞，硒或稀土成为可能。消解在密闭容器中进行，以防止挥发性汞或硒化合物的损失，并使用高度纯化（通过亚沸点蒸馏）的酸和在无颗粒环境（层流罩）中处理样品，以防止样品污染，这是考虑到低天然硒和汞浓度所必需的。所要求的样品制备设施将补充WLU新建的原子质谱（ICP-MS）设施，在该设施中，消化的样品将被测量汞，硒或稀土。拟议的样品制备设施（与正在建设的ICP-MS设施相结合）将实现两个主要目标。首先，它将是一个最先进的设施，可以开发和测试分析方法和样品制备方案。然后，这些方法和协议将被转移到更广泛的科学和实验室社区，以便它们可以在未来的研究中广泛使用，从而帮助产生更准确的环境信息。其次，我们随后将使用开发的方法自己对含有汞、硒或稀土的颗粒和胶体的环境和工业行为及其相关性进行选择的关键研究，从而更好地了解这些胶体和颗粒在这些元素的环境化学和毒理学中所起的作用。

Selenium (Se) and mercury (Hg) are among the most important trace elements that bioaccumulate and magnify in aquatic food chains, posing potential health risks to predatory waterfowl and fish, as well as human populations consuming those, all across Canada, especially in the vicinity of certain types of industrial operations. Rare earth elements (REEs) are of increasing technical importance in many semiconductor and electronics applications, and find their way increasingly into the environment via landfill leachate and mining activities, which necessitates (eco)toxicological studies to determine if REEs pose risks to aquatic organisms or humans. There is evidence that in all of these processes, Se, Hg and REEs are often associated with insoluble particles or colloids (= small particles that cannot be removed by filtration), but there are currently no adequate analytical methods to quantify concentrations of particulate or colloidal Hg, Se or REEs in waters. With the requested funding, we would create a sample preparation laboratory at Wilfrid Laurier University (WLU), in which water samples are pre-treated by microwave digestion to the point where accurate quantification of particulate or colloidal Hg, Se or REEs becomes possible. The digestion happens in closed vessels to prevent losses of volatile Hg or Se compounds, and uses highly purified (by sub-boiling point distillation) acids and sample handling in particle-free environments (laminar flow hoods) to prevent sample contamination, which is necessary given the low native Se and Hg concentrations. The requested sample preparation facility would complement the newly constructed atomic mass spectrometry (ICP-MS) facility at WLU, in which the digested samples will be measured for Hg, Se or REEs. The proposed sample preparation facility (in combination with the ICP-MS facility under construction) would serve two main goals. First, it would be a state-of-the-art facility, in which analytical methods and sample preparation protocols can be developed and tested. These methods and protocols would then be transferred to the broader scientific and laboratory communities, so that they can be used widely in future studies, and thereby help generate more accurate environmental information. Second, we will subsequently use the developed methods ourselves to conduct selected crucial studies on the environmental and industrial behavior and relevance of particles and colloids containing Hg, Se or REEs, and thereby obtain a better understanding of the roles that such colloids and particles play in the environmental chemistry and toxicology of these elements.