Results for multielement analysis of lunar soil and of seven rocks returned by Apollo 11 are presented. Sixty-six elements were determined with spark source mass spectrography and neutron activation. U. S. Geological Survey standard W-1 was used as a comparative stanadard. Results indicate an apparent uniformity of composition among the samples. Comparison with solar, meteoritic, and terrestrial abundances reveals depletiozt of volatile elements and enrichment of the rare earths titaniunm, zirconium, yttriuntm, and hafnium. Althouglh there is an overall similarity of the lunar material to basaltic achondrites amid basalts, the differences suggest detailed geochemical processes to the history of this material.
An experimental evaluation of the sources of error in rf spark mass spectrography is reported. For the copper standards studied, it is shown that heterogeneous distribution of the trace elements, random variations in the spark plasma, and densitometry errors are the prime contributors to the overall variations observed. Systematic variations in the spark plasma and irregularities between successive photoplates are generally insignificant in comparison.
A method has been devised for simultaneously determining the concentrations of La, Ce, and Pr in carbon steels. The samples are dissolved and their solutions sent through small amounts of ion exchange resin. The dried resin is pelletized and the L, X-ray fluorescence intensities of the rare earths are obtained. The intensities are compared to a curve obtained from previously prepared elemental standards. Precision of the standard curves is 8-14 rg, and detection limits are 0.002-0.0040/,, based on a 2-gram steel sample.THE USE of rare earths in steel has been primarily for inclusion shape control. The rare earth sulfides tend to form spherical
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