Analysis of pine needles by XRF scanning techniques

Concentrations of both essential and toxic elements in pine needles are known to be influenced by environmental factors, either directly from air pollutants or indirectly from acidification. In most previous work mean concentrations for bulk samples of pine needles have been reported. In this investigation, elemental distributions along the length of pine needles without any visible morphological damage were studied for a number of important elements. The needles were sampled from locations with essentially sandy soils of different pH in different parts of Latvia. The variation of element concentrations along the needle length proved to be very large for some elements, e.g. Zn and Mn, whereas it was almost constant for others, e.g. Cu and Fe. For some elements, large differences between needles of different age class were observed, and also variations with soil pH and light conditions. Healthy needles of the same age class growing under similar environmental conditions, have identical elemental concentration profiles. Scanning energy-dispersive x-ray fluorescence Spectrometry was used and the results were validated by independent analysis with graphite furnace atomic absorption spectrometry.