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岩石、土壤和水沉积物试样能够用氢氟酸、王水和氢溴酸——溴溶液分解。在两种氢溴酸浓度下,可采用二次MIBK(甲基异丁酮)萃取法自样品浸出液中萃取分离金、铊、铟和碲。金和铊首先从0.1M氢溴酸介质中萃取,然后在有抗坏血酸的情况下自3M氢溴酸介质中萃取钢和碲,以消除铁的干扰。随后可采用火焰原子吸收光谱法对各种元素进行测定。二次溶剂萃取法也可与电热原子吸收法一起使用,以降低地质物中料中四种金属的检出限。 金、铟、碲和铊在地质物料中含量极低。据估计,其在地壳中的丰度分别为:金0.001～0.0035ppm;铟0.11～0.14ppm;碲0.001ppm;铊0.3—1.3ppm。一种测定同一地质物料样品中所有四个元素含量的测试方法,在地化勘探中,能经济而快速地分析和检测岩石和风化产物中的矿物元素,并用其作为指示元素探明矿床的不同类型和研究元素的共生组合,因而具有特殊的优越性。 本文介绍的火焰原子吸收法,可提供一种相当迅速、简便的测定金、钢和碲的异常浓度(即比地壳丰度高许多)和铊的地壳丰度和异常浓度的方法。本法的特点是采用二次萃取,此时金和铊首先从0.1M氢溴酸的样品溶液中分离。然后铟和碲从3M氢溴酸介质中萃取,加抗坏血酸消除了铁的干扰。如采用电热原子吸收进行测定,四种元素的分析检出限还能相应地降低。
Rock, soil and water sediment samples can be hydrofluoric acid, aqua regia and hydrobromide-bromine solution decomposition. In both hydrobromic acid concentrations, secondary MIBK (methyl isobutyl ketone) extraction can be used to extract gold, thallium, indium and tellurium from the sample leachate. Gold and thallium were first extracted from the 0.1M hydrobromic acid medium and then extracted from 3M hydrobromic acid medium in the presence of ascorbic acid to eliminate iron interferences. Flame atomic absorption spectrometry can then be used to determine the various elements. Secondary solvent extraction can also be used with electrothermal atomic absorption spectrometry to reduce the detection limit of the four metals in the geological material. Gold, indium, tellurium and thallium are very low in geological materials. It is estimated that its abundance in the crust are: gold 0.001 ~ 0.0035ppm; indium 0.11 ~ 0.14ppm; tellurium 0.001ppm; Thallium 0.3-1.3ppm. A test method for determining the content of all four elements in a sample of the same geological material enables the economical and rapid analysis and detection of mineral elements in rock and weathering products in geochemical prospecting and uses it as an indicator element to determine the difference in mineral deposits The symbiotic combination of types and research elements therefore has particular advantages. The flame atomic absorption method described in this paper provides a fairly rapid and simple method for determining the anomalous concentrations of gold, steel and tellurium (ie much higher than the crustal abundance) and the crustal abundance and anomalous concentrations of thallium. This method is characterized by secondary extraction, when gold and thallium are first separated from the 0.1M hydrobromic acid sample solution. Indium and tellurium were then extracted from the 3M hydrobromic acid medium and the addition of ascorbic acid eliminated iron interference. Such as the use of electrothermal atomic absorption determination, the four elements of the detection limit can be reduced accordingly.