Analysis of botanical samples for 25 elements using an automated inductively-coupled plasma spectrometer

In one phase of Union Carbide Corporation's portion of the Uranium Resources Evaluation program, geochemists desired to investigate the correlation of the concentration of several elements in trees to their proximity to uranium ore deposits. This required multielement analysis of thousands of tree-branch samples at a minimum cost per sample. The concentration of the desired 25 elements ranged from ppM levels to major constitutents. Inductively-coupled plasma optical emission spectroscopy (ICP OES) was chosen as the analytical technique most capable of filling these requirements. The samples were dry ashed at 700/sup 0/C and the ash leached with water and HNO/sub 3/. The solution was diluted to an equivalent of 0.001 g ash/ml and analyzed on an automated ICP OES system. This paper describes the automated system and results obtained on spiked samples and NBS plant material standards.