Determination of trace elements on small geological samples fused in lithium tetraborate with x-ray fluorescence spectrometry

The determination of the trace elements Rb, Sr, Y, Zr, and Nb on small geological samples (100 mg) by x-ray spectrometry is discussed and results are shown. For previous major element analyses, the samples have been fused in Li2B4O7 (900 mg) and NaNO3 (200 mg) to form a glass disk with a thickness of approximately 1 mm. These relatively thin samples require a thickness correction for the x-ray intensities for energies higher than Fe Kα. Synthetic standards were used for calibration. Accuracy, estimated by comparison with international standards, is about 10% for concentrations between 20 and 100 ppM and 5% for concentrations of more than 100 ppM. 3 figures, 6 tables