A cryogenic laser ablation cell for trace metal and isotopic analyses of ice cores

点击翻译按钮获取中文摘要

The development of the new Canadian Ice Core Archive (CICA) at the University of Alberta, operational from Jan 2017, presents a unique opportunity to establish an on-site capability to measure the trace element and isotopic fingerprints of ice-borne dust in ice sheets across Canada and its arctic regions. Ice cores are key sources of data on past atmospheres, climate and climate changes, and on the rates, pathways and histories of atmospheric transport of natural dusts, aerosols and a diverse array of pollutants to Polar and high mountain regions. The relatively high accumulation rates of ice sheets compared to other proxies for climate change such as ocean sediments mean that the temporal resolution of data can be measured to unprecedented resolution, if new technological solutions can be found. Laser ablation micro-sampling coupled to ultra-sensitive plasma mass spectrometry is key to accessing this information at high temporal resolution. This proposal aims to establish a unique facility in Canada for the laser ablation analysis of ice core samples by acquisition of a custom-designed cryogenically cooled laser ablation cell that is fully compatible with existing state-of-the-art mass spectrometry and laser ablation hardware recently installed at the Arctic Resources Laboratory at the University of Alberta. The facility will enable the minimally destructive analysis of trace elements and isotopes of lead in ice cores. These geochemical proxies act as faithful fingerprints of the source of origin of dust particles. Adding the cryogenically cooled laser ablation cell and sample handling module to an existing deep UV laser ablation system will create a powerful need tool. In addition to maximizing, by orders of magnitude, the preservation of ice core during analysis, and attending new levels of temporal resolution, laser ablation offers a solution to the significant problems of preferential leaching that beset melting and solution analysis approaches. The new cryogenic ablation cell will be a centre-piece analytical capability for the national CICA facility, accessible to the Canadian and international visiting scientists. The cryogenic ablation cell will have broader applications in the measurement and source tracing of airborne pollutants around extraction resource industries and in the analysis of brain and other tissues. It will form a focus of HQP training in innovative new approaches to environmental analysis and monitoring. The cryogenic ablation facility would be investing in, and enhancing world class scientific infrastructure within Canada