酸溶分解-电感耦合等离子体质谱内标法测定地质样品中的痕量银

刘海明; 武明丽; 成景特

doi:10.15898/j.cnki.11-2131/td.202002190018

酸溶分解-电感耦合等离子体质谱内标法测定地质样品中的痕量银

Determination of Trace Silver in Geological Samples by Inductively Coupled Plasma-Mass Spectrometry with Acid Decomposition and Internal Standard Calibration

摘要

摘要: 应用电感耦合等离子体质谱法（ICP-MS）测定地质样品中的痕量银时，Zr、Nb、Mo的氧化物以及氢氧化物对银的两个质量数¹⁰⁷Ag和¹⁰⁹Ag造成严重的质谱重叠干扰，导致结果有明显的偏差。针对此问题，本文基于¹⁰⁷Ag的质谱干扰相对单一，只有⁹⁰Zr¹⁶OH⁺和⁹¹Zr¹⁶O⁺对¹⁰⁷Ag产生干扰，在ICP-MS分析中选用¹⁰⁷Ag对银进行测定。样品前处理中采用氢氟酸、高氯酸、硝酸敞开消解，在浸提液中加入过量氨水，将¹⁰⁷Ag的主要干扰元素Zr通过生成沉淀实现分离，以Re作内标补偿基体效应和信号漂移，采用ICP-MS测定了水系沉积物、岩石、土壤国家标准物质中痕量银的含量，测试值与认定值一致，方法检出限为0.0031μg/g，相对标准偏差（RSD）为4.38%。该方法简捷，在浸取液中加入氨水之前可以先测定常见金属元素，实现了浸取溶液的循环再利用。

Abstract:
BACKGROUNDInductively coupled plasma-mass spectrometry (ICP-MS) is used for the determination of trace silver in geological samples. Hydroxides and oxides of Zr, Nb, Mo cause serious overlapping interference on the two mass numbers of ¹⁰⁷Ag and ¹⁰⁹Ag, which can result in a significant deviation of the results.
OBJECTIVESTo develop a method for precise determination of trace Ag in geological samples.
METHODSConsidering that the MS interference of ¹⁰⁷Ag is relatively simple and only ⁹⁰Zr¹⁶OH⁺ and ⁹¹Zr¹⁶O⁺ have interferences on ¹⁰⁷Ag, ¹⁰⁷Ag was selected for the determination of silver in ICP-MS analysis. In the sample pretreatment, hydrofluoric acid, perchloric acid and nitric acid were used for open digestion, and excessive ammonia was added to the extraction solution. The main interference element Zr of ¹⁰⁷Ag was separated by precipitation. Trace silver was determined with Re as the internal standard to complement matrix effect and signal drift.
RESULTSThe content of trace silver in national standard materials of stream sediment, rock and soil was determined by ICP-MS. The test value was consistent with the certified value. The detection limit of the method was 0.0031μg/g, and the relative standard deviation (RSD) was 4.38%.
CONCLUSIONSThe method has the advantages of simple and accurate measurement of trace silver. Moreover, common metal elements can be determined before adding ammonia to the leaching solution, so that the extraction solution can be recycled.

HTML全文

参考文献(30)

施引文献

资源附件(0)