Application of laser-induced breakdown spectroscopy for heavy metal detection in aqueous solutions

Abstract

Water constitutes the essential basis for sustaining life. With the escalating contamination of global water resources, there exists a critical and immediate demand for a methodology enabling rapid, precise, and comprehensive elemental detection in aqueous solutions containing elevated concentrations of heavy metals. Traditional detection methods are plagued by limitations including intricate sample pretreatment procedures, prolonged detection cycles, and a heavy reliance on specialized laboratory conditions, thereby posing challenges for achieving micro-scale, in-situ, and dynamic distribution detection and analysis. Laser-Induced Breakdown Spectroscopy (LIBS) technology has emerged as one of the premier techniques for detecting heavy metals in aqueous solutions, owing to its distinctive advantages, including the elimination of complex sample preparation, simultaneous multi-element detection, rapid analysis, and the capability for remote in situ operation. However, the direct detection of aqueous solutions using LIBS suffers from issues such as liquid splashing, plasma quenching, inhomogeneous elemental distribution, and laser energy loss, resulting in insufficient detection sensitivity, accuracy, and stability. This paper systematically reviews the key technological advances of LIBS in the detection of heavy metals in aqueous solutions and comprehensively summarizes the principles, advantages, application performance, and representative research results of various technical routes from four core perspectives: sample pretreatment, detection system optimization, data processing and combined techniques. Meanwhile, the challenges faced by LIBS in the determination of heavy metals in aqueous solutions are concluded, and its future development trends toward miniaturization, intellectualization, and multi-technology integration are prospected. This review aims to provide a comprehensive reference for the further optimization and practical application of LIBS in the monitoring of heavy metal pollution in aquatic environments.