Copper Transport and Accumulation in Spruce Stems (Picea abies (L.) Karsten) Revealed by Laser-Induced Breakdown Spectroscopy

Laser-Induced Breakdown Spectroscopy (LIBS) in double pulse configuration (DP LIBS) was used for scanning elemental spatial distribution in annual terminal stems of spruce (Picea abies (L.) Karsten). Cross sections of stems cultivated in Cu2+ solution of different concentrations were prepared and analyzed by DP LIBS. Raster scanning with 150 mu m spatial resolution was set and 2D (2-dimentional) maps of Cu and Ca distribution were created on the basis of the data obtained. Stem parts originating in the vicinity of the implementation of the cross sections were mineralized and subsequently Cu and Ca contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results provide quantitative information about overall concentration of the elements in places, where LIBS measurements were performed. The fluorescence pictures were created to compare LIBS distribution maps and the fluorescence intensity (or the increase in autofluorescence) was used for the comparison of ICP-MS quantitative results. Results from these three methods can be utilized for quantitative measurements of copper ions transport in different plant compartments in dependence on the concentration of cultivation medium and/or the time of cultivation.