Non-target analysis of radicals in sonochemical and advanced oxidation processes (AOPs)

一些化学和生物过程涉及短寿命的自由基，这些自由基要么由反应产生，要么由能量源与物质相互作用产生。到目前为止，大多数自由基的形成机制及其命运仍然难以理解，因为它们的寿命很短。Boffito教授和Yargeau教授团队的几个研究项目就是这样的情况，这些项目涉及通过超声波化学或高级氧化氧化还原过程(AOPS)产生的自由基。在声化学过程中，超声波(20 kHz-1 MHz)传递的能量会产生声空化，即稀薄气体微泡的形成、生长和破裂。它们的坍塌导致了微热点(高达5000K和1000atm)和高速喷流(100m S-1)。在这些条件下，就形成了自由基。它们的类型和浓度取决于几个因素，如超声波设备的特性和反应介质的物理化学特性。由此产生的自由基可以被用来强化几个化学和物理过程，包括AOPS。AOPS描述了一大类氧化过程，通过以不同方式产生的自由基来非选择性地降解有机污染物。这些方法包括臭氧氧化、等离子体氧化、电化学氧化、化学氧化、光催化、声化学和组合AOPS。我们需要一台便携式电子自旋共振(ESR)分光光度计来检测自由基。ESR是识别和量化声化学过程中所涉及的自由基的关键，不仅是建立声化学的机制(目前仍被很大程度上忽视)的关键，也是设计高效的声化学反应器的关键，以最大限度地提高产率和选择性，同时将能量需求降至最低。同样，量化AOPS中的活性氧化物种和中间体对于设计更有效的AOP系统和确定新出现的关注污染物(CECs)的降解机理至关重要。这允许设计完全矿化污染物的方法，从而不会产生残留的生态毒性。加拿大没有便携式电子沉降仪。加拿大有5个机构提供非便携式ESR，但需要重新定位反应堆。我们预计，许多不同的研究小组将要求学术界和工业界访问ESR。ESR用于研究酶的活性和自由基对组织的损伤，用于绝对测年的地质研究，以及用于产品稳定性和保质期质量控制的工业应用。它还将有助于与学术界和工业界合作伙伴发展新的合作。此次收购将极大地提高至少20名HQP的研究质量，并为他们提供适销对路的技能，不仅可以在科学研究中工作，还可以在制药和个人护理部门、水修复、塑料、纤维和食品等商业部门工作。

Several chemical and biological processes involve short-lived radicals that are either generated by a reaction or the interaction of a source of energy with the matter. To date, most mechanisms of the radical formation and their fate are still elusive to understand due to their short lifetime. This is the case for several research projects in the teams of Prof. Boffito and Yargeau, which involve radicals generated either sonochemically or by advanced oxidation redox processes (AOPs). In sonochemical processes, the energy transmitted by ultrasound (20 kHz - 1 MHz) produces acoustic cavitation, i.e. the formation, growth, and collapse of rarefied gas micro-bubbles. Their collapse results in micro hot spots (up to 5000 K and 1000 atm), and high speed jets (100 m s-1). In these conditions, radicals form. Their type and concentration depends on several factors, such as the characteristics of the ultrasound equipment and the physico-chemical identity of the reaction medium. The radicals thus generated can be leveraged to intensify several chemical and physical processes, including AOPs. AOPs describe a broad family of oxidation processes to unselectively degrade organic pollutants by radicals generated in different ways. These include ozonation, plasma, electrochemical oxidation, chemical oxidation, photocatalysis, sonochemistry, and combined AOPs. We request a portable electron spin resonance (ESR) spectrophotometer for the detection of free radicals. ESR is key to identify and quantify the radicals involved in sonochemical processes not only to establish the mechanisms of sonochemistry, which are still largely ignored, but also to design efficient sonochemical reactors to maximize yield and selectivity while minimizing energy requirements. Similarly, quantifying reactive oxidation species and intermediates in AOPs is crucial to design more efficient AOP systems and to identify the degradation mechanisms of contaminants of emerging concern (CECs). This allows to design methods to completely mineralize pollutants leading to no residual ecotoxicity. There are no portable ESR apparatuses in Canada. Non-portable ESR are available in 5 Canadian institutions but require re-locating reactors. We anticipate that many different research groups will request access to the ESR both from academia and industry. ESR finds application to investigate the activity of enzymes, and tissue damage by free radicals, in geological studies for absolute dating and in industrial applications for quality control of product stability and shelf-life. It will also help developing new collaboration with both academic and industrial partners. The acquisition will greatly enhance the quality of the research of at least 20 HQP and provide them with marketable skills to work not only in scientific research but also in commercial sectors such as pharmaceuticals and personal care sectors, water remediation, plastics, fibers, and food products.