Development of a laser-induced breakdown spectroscopy method for the issues of geological exploration and ecological monitoring of aquatic environments in real time 

Dmitriy Yu. Proshchenko, Candidate of physical and mathematical sciences, senior staff scientist, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia); programming engineer, Institute of Automation and Control Processes of the Far Eastern branch of the Russian Academy of Sciences (5 Radio street, Vladivostok, Russia), E-mail: dima.prsk@mail.ru
Sergey S. Golik, Candidate of physical and mathematical sciences, leading researcher, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia); senior staff scientist, Institute of Automation and Control Processes of the Far Eastern branch of the Russian Academy of Sciences (5 Radio street, Vladivostok, Russia), E-mail: golik_s@mail.ru
Aleksandr Yu. Mayor, Doctor of engineering sciences, leading researcher, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia); leading researcher, Institute of Automation and Control Processes of the Far Eastern branch of the Russian Academy of Sciences (5 Radio street, Vladivostok, Russia), E-mail: mayor@iacp.dvo.ru
Aleksey A. Il'in, Candidate of physical and mathematical sciences, leading researcher, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia); senior staff scientist, Institute of Automation and Control Processes of the Far Eastern branch of the Russian Academy of Sciences (5 Radio street, Vladivostok, Russia), E-mail: ilyin@iacp.dvo.ru
Anton V. Borovskiy, Postgraduate student, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia), E-mail: ifitfizik@gmail.com
Oleg A. Bukin, Doctor of physical and mathematical sciences, professor, leading researcher, Far Eastern Federal University (10 Ajax bay, Russian Island, Primorsky Kray, Russia), E-mail: o_bukin@mail.ru 

543.423 

10.21685/2072-3040-2021-1-9 

Background. Currently, the priority task is to develop the resources of the continental shelf. At the same time, ensuring the environmental safety of marine areas remains an important aspect. In this regard, the development and creation of robotic systems equipped with specialized complexes capable of solving a wide functional range of underwater operations is relevant. The purpose of this work is to create a hardware and software complex based on the method of laser-induced breakdown spectroscopy with the possibility of integrating it into a remotely operated underwater vehicle of the survey class for measuring the elemental composition of seawater and bottom rocks in the In Situ mode.
Materials and methods. The analysis of the elemental composition of seawater and soil samples was carried out using the laser-induced breakdown spectroscopy method. A two-pulse diodepumped Nd: YAG laser DF-251 (SOL Instruments) was used as a source of laser plasma excitation.
Results. An experimental hardware and software complex of an underwater spectrometer based on the method of laser-induced breakdown spectroscopy with the possibility of integrating it into existing remotely operated underwater vehicle (ROV) of the inspection class has been developed. Laboratory experiments were carried out to determine the chemical composition of a seawater sample. The possibility of using the presented hardware and software complex in the tasks of environmental monitoring of sea areas and geological exploration is shown.
Conclusions. The obtained laboratory results make it possible to assert that the developed hardware and software complex is a promising solution for application in the problems of environmental monitoring of sea areas and geological exploration. 

spectroscopy, laser induced breakdown spectroscopy, plasma, environmental monitoring, geological exploration 

1. Hahn D.W., Omenetto N. Review of basic diagnostics and plasma–particle interactions: still-Laser-induced breakdown spectroscopy (LIBS), part I: review challenging issues within the analytical plasma community. Applied spectroscopy. 2010;64(12): 335A–366A.
2. Martínez G.M., Renno N.O. Water and brines on Mars: current evidence and implications for MSL. Space Science Reviews. 2013;175(1–4):29–51.
3. Damon E.K., Tomlinson R.G. Observation of ionization of gases by a ruby laser. Applied Optics. 1963;2:546–547.
4. Tian Y., Hou S., Wang L., Duan X., Xue B., Lu Y. CaOH Molecular Emissions in Underwater Laser-Induced Breakdown Spectroscopy: Spatial–Temporal Characteristics and Analytical Performances. Analytical chemistry. 2019;91(21):13970–13977.
5. Sakka T., Takatani K., Ogata Y.H., Mabuchi M. Laser ablation at the solid – liquid interface:
transient absorption of continuous spectral emission by ablated aluminium atoms. Journal of Physics D: Applied Physics. 2001;35(1):65.
6. Thornton B., Takahashi T., Sato T. Development of a deep-sea laser-induced breakdown spectrometer for in situ multi-element chemical analysis. Deep Sea Research Part I: Oceanographic Research Papers. 2015;95:20–36.
7. Golik S.S., Ilyin A.A., Kolesnikov A.V. The influence of laser focusing on the intensity of spectral lines in femtosecond laser-induced breakdown spectroscopy of liquids. Technical Physics Letters. 2013;39(8):702–704.