Elemental analysis of halogens using molecular emission by laser-induced breakdown spectroscopy in air

•We studied laser induced breakdown spectra of halogens with alkali-earth elements.•Emission and temporal behavior of CaF and CaCl molecules were determined.•Sensitivity of F and Cl detection by molecules and atoms was compared.

Fluorine and chlorine do not produce atomic and ionic line spectra of sufficient intensity to permit their detection by laser-induced breakdown spectroscopy. They do, however, combine with alkali-earths and other elements to form molecules whose spectra may be easily identified, enabling detection in ambient conditions with much higher sensitivity than using F I and Cl I atomic lines.