DETERMINATION OF THE RARE-EARTH ELEMENTS IN GEOLOGICAL-MATERIALS BY INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY
DETERMINATION OF THE RARE-EARTH ELEMENTS IN GEOLOGICAL-MATERIALS BY INDUCTIVELY COUPLED PLASMA MASS-SPECTROMETRY
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DOI：
10.1021/ac00135a018
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发表时间：
1987-04-15
影响因子：
7.4
通讯作者：
CROCK, JG
中科院分区：
文献类型：
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作者：
LICHTE, FE;MEIER, AL;CROCK, JG
本文介绍了电感耦合等离子体质谱（ICP-MS）测定地质样品中稀土元素的分析方法。对仪器参数和影响分析结果的因素进行了研究和优化。样品经酸消化后直接分析，无需分离或预浓缩，检出限为2-11 ng/g，精密度为±2.5%相对标准偏差，准确度与电感耦合等离子体发射光谱法和仪器中子活化分析相当。使用市售ICP-MS仪器，并对样品引入系统、炬和取样器孔进行修改，以减少由地质材料制备的样品溶液的高盐含量的影响。本文对氧离子和其它双、三原子离子的等压干扰作了数学校正。特殊的内标程序用于补偿金属氧化物比率和灵敏度的漂移。参考标准值用于验证方法的准确性和实用性。地质样品中稀土元素（REE）的测定有几种分析方法（1-3）。目前，最广泛使用的两种方法是仪器中子活化分析（INAA）（4）和电感耦合等离子体原子发射光谱法（ICP-AES）（5，6）。中子活化分析由于其高灵敏度而特别有用。当与放射化学分离相结合时，该技术提供了高灵敏度和优异的准确性。该技术的主要缺点是每次分析的时间和成本。ICP-AES法比INAA法更普遍，但涉及REE的详细研究必须利用离子交换技术从基质中分离和浓缩REE。这一步骤减少了光谱干扰，并提供了显着的预富集的稀土比直接消化程序。然而，离子交换步骤增加了分析时间，并且需要使用高纯度的酸和试剂以将污染保持在最低限度。灵敏度足以确定大多数稀土元素的丰度等于或高于碳酸盐丰度（5）。
A method of analysts of geologicalmaterials for the determination of the rare-earth elements using the Inductively coupled plasma mass spectrometrlc technique (ICP-MS) has been developed. Instrumental parameters and factors af-fecting analytical results have been first studied and then optimized. Samples are analyzed directly following an acid digestion, without the need for separation or preconcentration with limits of detection of 2-11 ng/g, precision of±2.5% relative standard deviation, and accuracy comparable toIn-ductively coupled plasma emission spectrometry and Instrumental neutron activation analysis. A commercially available ICP-MS Instrument Is used with modifications to the sample introduction system, torch, and sampler orifice to reduce the effects of high salt content of sample solutions prepared from geologic materials. Corrections for Isobarlc Interferences from oxide ions and other diatomic and triatomic Ions are made mathematically. Special internal standard procedures are used to compensatefor drift in metakmetal oxide ratios and sensitivity. Reference standard values are used to verify the accuracy and utility of the method.Several methods of analysis existfor the determination of the rare-earth elements (REE) in geological materials (1-3). Currently, the two methods most widely used are instrumental neutron activation analysis (INAA)(4) and inductively coupled plasma atomic emission spectrometry (ICP-AES)(5, 6). Neutron activation analysis is particularly useful because of its high sensitivity. When coupled with radiochemical sepa-ration, this technique offers both high sensitivity and excellent accuracy. The primary drawbacks of the technique are the time andcost for each analysis. The ICP-AES method is more generally available than INAA but detailed studies involving REE must utilize an ion-exchange technique for separation and concentration of the REE from the matrix. This step reduces spectral interferences and offers significant precon-centration of the REE over straight digestion procedures. However, the ion-exchange step increases the time of the analysis and requires the use of high-purity acids and reagents to keep contamination to a minimum. The sensitivity is sufficient to determine most of the REE at or above chondritic abundance (5).