Anomalous behaviour of the non-selective ionisation signal pulse under laser ablation into a flame

When applying to the probing electrode the potentials with the different po larity one can notice that the non-selective and selective signals behave q uite differently. In case of the positive potential compared with the negat ive one the non-selective signal shows anomalous behavior: it changes the s hape and polarity and its amplitude increases dramatically while the select ive one only changes the polarity that can be explained by the electrical p roperties of the flame reaction zone, which effectively eliminates the char ges from laser plasma by the recombination.