An Energy-dispersive Miniprobe Multielement Analyzer (EMMA) for direct analysis of Pb and other trace elements in peats
An Energy-dispersive Miniprobe Multielement Analyzer (EMMA) for direct analysis of Pb and other trace elements in peats
复制标题
用于直接分析泥炭中 Pb 和其他微量元素的能量色散微型探针多元素分析仪 (EMMA)
DOI：
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发表时间：
1996
影响因子：
4.3
通讯作者：
W. Shotyk
中科院分区：
文献类型：
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作者：
A. Cheburkin;W. Shotyk
设计并建造了一台能量色散微探针多元素分析仪（EMMA），用于岩石中单个矿物颗粒等小样品（如50 μm）中微量元素（As，Cr，Cu，Fe，Ga，Ge，Hf，Mn，Ni，Pb，Rb，Se，Sr，Th，Y，U，Zn）的灵敏、快速、无损分析。这里描述了EMMA仪器的另一种配置，用于更大的样品，如煤粉，土壤，沉积物和植物材料。为了尽量减少异质性问题，通过安装不同的准直器使用更大的X射线束尺寸（0.1 × 6 mm），样品保持器每分钟旋转25次。使用这种方法，Rb，Sr，Cu，Zn和Pb的泥炭样品收集在瑞士和苏格兰北方的沼泽地进行了测量。例如，Pb的检测限约为0.3 μg/g，比传统的XRF分析仪好一个数量级。为了进行比较，还使用GFAAS测量了相同样品的酸蚀剂中的Pb。使用EMMA获得的铅结果与大陆泥炭样品的GFAAS数据相当。然而，在富含Cl的样品从海洋沼泽，GFAAS信号被强烈抑制，和两种方法的准确比较是不可能的。因此，EMMA技术与传统的GFAAS相比具有三个优点：第一，不需要样品溶解;第二，同时测定几种感兴趣的元素;第三，EMMA技术不受基质干扰。
An Energy-dispersive Miniprobe Multielement Analyzer (EMMA) was designed and constructed for sensitive, rapid, and non-destructive analysis of trace elements (As, Cr, Cu, Fe, Ga, Ge, Hf, Mn, Ni, Pb, Rb, Se, Sr, Th, Y, U, Zn) in small (e.g. 50 μm) samples such as individual mineral grains from rocks. An alternative configuration of the EMMA instrument is described here for use with larger samples such as powders of coal, soil, sediments, and plant materials. To minimize heterogeneity problems, a larger X-ray beam size (0.1 × 6 mm) was used by installing a different collimator, and the sample holder rotated 25 times per minute. Using this approach, Rb, Sr, Cu, Zn and Pb were measured in peat samples collected from bogs in Switzerland and northern Scotland. The detection limit for Pb, for example, is approximately 0.3 μg/g which is one order of magnitude better than conventional XRF analyzers. For comparison, Pb was also measured in acid digests of the same samples using GFAAS. The Pb results obtained using EMMA are comparable to the GFAAS data for the continental peat samples. However, in the Cl-rich samples from the maritime bogs, the GFAAS signal was strongly suppressed, and an accurate comparison of the two methods was not possible. The EMMA technique, therefore, has three advantages over conventional GFAAS: first, no sample dissolution is required; second, several elements of interest are determined simultaneously; and third, the EMMA technique is not subject to matrix interferences.