(Table 1, page 1376) Chemical analyses of manganese nodules and crusts from the Pacific Ocean

A compilation of chemical analyses of Pacific Ocean nodules using an x-ray fluorescence technique. The equipment used was a General Electric XRD-5 with a tungsten tube. Lithium fluoride was used as the diffraction element in assaying for all elements above calcium in the atomic table and EDDT was used in conjunction with a helium path for all elements with an atomic number less than calcium. Flow counters were used in conjunction with a pulse height analyzer to eliminate x-ray lines of different but integral orders in gathering count data. The stability of the equipment was found to be excellent by the author. The equipment was calibrated by the use of standard ores made from pure oxide forms of the elements in the nodules and carefully mixed in proportion to the amounts of these elements generally found in the manganese nodules. Chemically analyzed standards of the nodules themselves were also used. As a final check, a known amount of the element in question was added to selected samples of the nodules and careful counts were taken on these samples before and after the addition of the extra amount of the element. The method involved the determination and subsequent use of absorption and activation factors for the lines of the various elements. All the absorption and activation factors were carefully determined using the standard ores. The chemically analyzed samples of the nodules by these methods yielded an accuracy to at least three significant figures.

本数据集为采用X射线荧光（X-ray Fluorescence, XRF）技术开展的太平洋锰结核化学分析汇总成果。所用设备为配备钨靶管的通用电气（General Electric）XRD-5型仪器。氟化锂作为衍射元件，用于分析元素周期表中原子序数高于钙的所有元素；而EDDT则配合氦气路径，用于分析原子序数低于钙的所有元素。在采集计数数据时，采用流气计数器（Flow Counters）配合脉冲高度分析器，以剔除不同阶次但符合整数阶的X射线谱线干扰。研究者证实该设备稳定性极佳。设备校准采用标准矿样：该类矿样由结核中各元素的纯氧化物制备而成，并按照锰结核中常见的元素含量比例精准混合；同时亦采用经化学分析的结核样品标准物质作为校准参照。作为最终验证环节，研究者向选定的结核样品中加入已知量的目标元素，并分别在添加前后对样品进行精准计数测量。本方法需先测定各元素谱线的吸收系数与活化因子，并将其应用于后续分析；所有吸收系数与活化因子均通过标准矿样精准测定。采用上述方法对结核样品进行化学分析所得结果的准确度至少可达三位有效数字。