MULTIELEMENT ANALYSIS OF PLANTS BY WDXRF USING THE SCATTERED RADIATION CORRECTION METHOD

Following the evolution of plants (their growth, nutrient deficiency, food value etc.) requires the determination of their elemental content s. One needs to determine the chemical composition of plants in order to estimate their impact on biomass burning emissions, one of the most important sources of atmospheric pollution, especially in the tropics . To obtain the multi-element composition of plant samples, a procedur e using x-ray fluorescence spectrometry was developed. The matrix effe cts affecting the relationship measured intensities vs. concentrations were corrected by the scattered radiation method. Specimen preparatio n requires only 300 mg of dried and finely ground material for the sim ultaneous determination of Na, Mg, P, S, CI, K, Ca, Mn and Fe in refer ence materials and in savannah grasses (the samples of interest). The whole experimental procedure is carried out in less than 5 min. The ma in advantage of the method is the non-modification of the original sam ple, either during specimen preparation or in the exciting x-ray beam. Therefore, storage and complementary analyses of the prepared specime ns are possible. For savannah grasses, which can contain relatively hi gh concentrations of silica, Si has also been determined, but by means of a glass-disc preparation from 100 mg of sample powder. (C) 1997 by John Wiley & Sons, Ltd.