Novel optical method based on nebulization assisted laser induced plasma on inexpensive paper substrates for online determination of halogens and metals in liquid samples.

[Display omitted] • A LIBS methodology for liquid sample analysis was developed and tested. • Common paper sheets are a convenient Ca source for molecular recombination. • Nanosecond-laser ablation is capable of breaking strong fluorine-carbon bonds. • Nebulization-assisted LIBS can be implemented for online screening of halogens. Halogen determination in liquid matrices with Laser-Induced Breakdown Spectroscopy (LIBS) is still a largely unexplored area of research. Together with the intrinsic problematics of liquid samples in LIBS analysis, halogen atomic emission is hard to observe without experimental modifications (e.g. vacuum chambers for VUV resonant lines or controlled He atmospheres for enhanced IR lines) or without switching to indirect determination via halide molecules emission. For the latter, the presence of an alkali-earth metal element is necessary. Previous works have explored CaCO 3 pellets as a substrate provider of Ca, and a nebulization-assisted methodology, with great potential for online implementation, has been successfully tested with synthetic and real F-containing samples. However, manufacturing pellets is a time- and reagent-consuming process not suitable for an online analysis technique and a more convenient substrate is needed. In the present work, different kinds of paper, from regular office paper to oil-painting sheets, are tested to explore its feasibility as a Ca-containing solid target. Different sources of F were also considered including inorganic fluoride and fluorocarbon containing samples. Moreover, both fluorine and chlorine determination via molecular emission are considered, achieving limits of detection (LODs) of 5 ppm and 192 ppm, respectively; a common metal (Zn) is also determined via atomic emission to test its validity for multi-elemental microanalysis, with a LOD of 5 ppm. [ABSTRACT FROM AUTHOR]