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

•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.