The density of Li atoms in the plume generated by laser ablation of LiNbO3 has been studied using optical absorption spectroscopy in different environments (vacuum, Ar, O-2 and N2O). The results show that the density of Li atoms in the plume decreases when ablation takes place in a N2O environment. The analysis of the structure and composition of films grown under the considered environments shows that: (i) the Li content of the films remains approximately constant in all cases, (ii) the oxygen content for films grown in an oxidant environment (O-2 and N2O) increases, and (iii) the formation of niobium nitride is observed in a N2O environment. The results are discussed in terms of possible chemical reactions occurring in the plume in the presence of the considered gases,