Elemental analysis of liquid samples by laser induced breakdown spectroscopy (LIBS): Challenges and potential experimental strategies

Despite the growing interest of research in the trace element detection in liquids via laser-induced breakdown spectroscopy (LIBS), the measurement of the ultra-low concentration of trace elements remains a challenge due to splashing, plasma cooling which in turn leads to shorter plasma lifetime. However, due to the promising emerging applications of this technique in environmental and biomedical sciences, researchers are exploring various strategies to improve the detection limits in liquid sample studies. This work is an overview of potential experimental strategies used for liquid LIBS studies and serves to describe the progress made in adopting different experimental configurations to implement the said studies for trace element detection in various application fields. Further, the development in the various sampling techniques to achieve a higher limit of detection with reproducible results are addressed here. The challenges and benefits related with various experimental schemes and sampling approaches as well as some innovative approaches that have been established recently to improve sensitivity and detection limits are highlighted using examples from the literature. The problems that remain in the liquid LIBS analysis are also discussed and an outlook for the future is featured at the end of the article.