Plasma emission spectra were investigated at laser breakdown on the surface of sea water within 30 s. Atomic hydrogen absorption lines are identified in the spectral? region 375-390 nm. Signal-to-background ratio and emission dynamics of molecular bands CN, OH and resonance doublets of Na, Ca, and Mg were investigated. The results indicates that time dependence of signal-to-background ratio (Na, Ca, Mg) and intensity of continuum, Na, Mg, OH and CN are best fitted with two exponential decay times, Ca - with single exponential decay time.
laser spark spectroscopy; emission spectrum; see water