Laser-induced breakdown spectroscopy characterization of tree rings from the Popocatépetl volcano area, Mexico

摘要： Laser-induced breakdown spectroscopy (LIBS) was used to monitor macro- and micro-nutrients in pine trees exposed to two mayor activity periods of the Popocatépetl volcano in Mexico. Due to the high spatial resolution achieved with LIBS, a separate analysis of earlywood and latewood was performed. An increased concentration of potassium was found in earlywood, while calcium and sodium decreased. Besides, it was observed a similar temporal behavior for elements belonging to the same chemical group. The alkali earth metals Ca, Mg and Sr showed decreasing trends through the investigated years while alkali metals Na and K remain nearly constant. LIBS was able to detect signi?cant changes in Ca, Mg, Na and Sr intensities coincident with the 1919 Popocatépetl's eruptive period and after the volcanic activity starting at the end of 1999. Temporal evolution of the emission intensities is in agreement with the elemental composition obtained with inductively coupled plasma optical emission spectrometry.