Purchase of a tandem LA-LIBS femtosecond laser system for the UK

Earth and environmental scientists tackle diverse issues ranging from the formation of Earth to the fate of ecosystems being stressed by pollution. This requires us to measure the chemical composition of many different samples, including minerals, plastics, dust, and biological materials; this allows us to link physical and biological process (e.g. growth of minerals, breakdown of plastic in the environment, corrosion, dispersal of dust) with chemical ones (e.g. uptake of metals in minerals, release of toxic elements from plastics, transfer of polluting chemicals to plants and animals). Only then can we fully determine sustainable solutions to complex environmental problems, such as (1) how to locate and sustainably mine metals that are critical for building low-carbon infrastructure, (2) how dangerous microplastics are in rivers and oceans, and (3) how to reduce harmful air pollution. Measurement of such a broad range of materials usually requires a multitude of different instruments and methods. In addition, for many materials (e.g. plastic, dust) it is difficult to measure very small fragments in a controlled way. We propose the use of a new instrument, the first of its kind in the UK, that will allow analysis of a vast range of Earth materials and difficult to measure elements to provide high quality data critical for addressing geo-environmental problems.

The new instrument capitalises on recent innovations in laser technology, bringing together ultrafast femtosecond laser ablation (fs-LA) with laser induced breakdown spectroscopy (LIBS) into a single system (fs-LA-LIBS). It is uniquely capable of analysing a wide range of materials, as the very short duration pulse laser (femtosecond (fs) or one quadrillionth of a second!) ejects only a very thin surface layer of material and does not heat the sample below. This allows sensitive materials, such as plastic, liquids, biological samples and dust, to be rapidly analysed for their chemical composition. This is measured simultaneously in two ways: 1) LIBS - the laser energy ejects and excites atoms, which emit optical radiation (light) as they cool. Spectrometers measure the wavelength of this optical radiation and convert it into a chemical analysis of the sample, including for elements such as non-metals that are very difficult to measure in other ways. 2) LA - the tiny volume of ejected sample is swept away by a stream of gas into a mass spectrometer, where it enters a 7000degC plasma, (as hot as the Sun's surface), breaking down any remaining molecules and producing charged ions. These are separated by the mass spectrometer according to their mass and charge, providing highly-sensitive measurement of the concentration of trace elements and ratios of different isotopes in the sample.

The combination of these technologies in one instrument capable of rapid analysis will be unique to the UK and Europe, and will provide the data required to tackle many major environmental challenges.