Dr. Elton Sores de Lima Filho is currently a Research Officer with the Energy, Mining and Environment Research Centre (EME) at the National Research Council of Canada (NRC). His work focus is developing optical instruments for the measurement of materials properties. Dr. Soares de Lima Filho received his Ph.D. in Engineering Physics at Polytechnique Montreal and did his post-doctoral work at the COPL – Université Laval.
Selenium is found naturally in metal sulfide ores (copper, nickel, lead) and is needed in trace amounts for proper cellular function in humans and many animals. Selenium can concentrate in runoff near ore mines and is toxic to humans and animals when found in concentrated quantities. The National Research Council of Canada’s (NRC) Energy, Mining and Environment Research Centre (EME) has been working on a process to improve real-time testing for selenium content in mining effluents and the output of water treatment plants.
In the recent paper titled Trace Selenium measurement in Water Using Laser-Induced Fluorescence Assisted by Laser Ablation, the NRC’s Dr. Elton Soares de Lima Filho and his team report on their findings of a novel way to do this testing in situ. Current methods of measuring selenium content are labor-intensive and costly; requiring sampling procedures and transportation of samples that make them prone to contamination.
The NRC team has found that using LA-LIF (laser ablation-assisted laser-induced fluorescence), as opposed to traditional LIBS (laser-induced breakdown spectroscopy) improves the limits of detection. This breakthrough would combine the real-time capabilities of LIBS with the enhanced sensitivity of LIF to provide a new tool for inline monitoring of selenium in mining effluents and water treatment facilities.
Q&A with Dr. de Lima Filho:
What do you enjoy most about your work with the NRC’s Energy, Mining and Environment Research Centre?
It is a very fulfilling experience to be able to see research efforts become real-world applications that have an impact for Canada, and at the NRC, I can (and have to) do exactly that. Working at the Energy, Mining and Environment Research Centre, I have the opportunity to address some pressing issues that affect the environment and provide technologies that help the Canadian industry increase efficiency and sustainability. I get to address real-world problems, and to select through a pool of novel sensing technologies and integrate them into palpable prototypes.
Where do you see this technology (for effluent testing) in 10 years?
Water characterization both in effluents, as well as water treatment processes will profit from a greater accessibility of in the field analytical techniques in the next decade. LIBS and LA-LIF allow much faster, cheaper and environmentally friendly testing than laboratory techniques. Those techniques are advancing at large steps thanks to the miniaturization of laser sources, electronics and spectrometers and advances in artificial intelligence. We already see today handheld LIBS systems being employed to provide in situ real-time analysis in many fields. I believe it is just a matter of time that LA-LIF will go through the same path. This will augment the set of tools that we already use towards very high sensitivity, which is needed to assess, for example, water contaminants.
How has the OPOTEK Opolette been useful in your research?
In order to perform LA-LIF, we use two lasers, one for atomizing the sample, and a second laser to excite the atom of interest, which will in turn emit its characteristic fluorescence. For the excitation, we irradiated the atomized sample with a laser beam coming from a tunable laser source: an Opolette DUV optical parametric oscillator which emitted nanosecond pulses at the deep-ultraviolet 196.09 nm excitation wavelength.