摘要
金的元素活动态是用来指示隐伏金矿床的有效方法,将各相态金完全提取、准确定量分析,可以清晰、明显地指示地壳深部金矿床的有效信息。金的元素活动态提取液经过王水处理后,采用泡塑吸附-硫脲解脱的方式将金分离富集,解脱溶液一般采用石墨炉原子吸收光谱(GF-AAS)法测定,该方法效率低、检出限高、精密度差,数据可信度降低。采用电感耦合等离子体质谱(ICP-MS)法测定可以有效避免GF-AAS法的缺点,实验采用低浓度的硫脲解脱液(0.2 g/L),能够将1000 ng的金完全解脱,低浓度的硫脲溶液也保证了仪器的长期稳定性;标准溶液采用和提取溶液一致的处理方法(王水分解+泡塑吸附+硫脲解脱),提高了测定结果的准确度。方法得到了水溶态、黏土吸附态、有机结合态、铁锰氧化物态的检出限分别为0.012、0.006、0.006、0.014μg/kg,方法的相对标准偏差为4.6%~18.2%,各相态加和结果和全量的相对误差的绝对值均小于4.9%,表明提取方法和分析方法准确可靠。
The determination of gold in the active state of elements is an effective method to find concealed gold deposits.The complete extraction and accurate quantitative analysis of gold in various phases can clearly indicate the effective information of gold deposits in deep crust.After pretreatment with aqua regia,gold was separated and enriched by foam plastic adsorption and thiourea desorption method.The extracting solution is usually determined by graphite furnace atomic absorption spectrometry(GF-AAS).This method is low efficiency,high detection limit,poor precision and low reliability.Inductively coupled plasma mass spectrometry(ICP-MS)can effectively avoid the shortcomings of GF-AAS method.Low concentration of thiourea solution(0.2 g/L)was used in this method,which could completely desorb 1000 ng gold at most.At the same time,the low concentrate of thiourea solution also ensured the long-term stability of the instrument.The standard solution adopts the same pretreatment method as the extracting solution(aqua regia decomposition,foam plastic adsorption and thiourea solution desorption),which improves the accuracy of the determination results.By this method,the detection limits of water-soluble state,clay-absorbed form,bound organic,iron-manganese oxidized state were 0.012,0.006,0.006,0.014μg/kg,respectively,and the precision of this method was 4.6%—18.2%.The absolute value of the relative errors of the sum results of each phase state and the total amount are less than 4.9%,indicating that the extraction method and the analysis method are accurate and reliable.
作者
杨菊
唐瑞玲
徐进力
YANG Ju;TANG Ruiling;XU Jinli(Regional Geology Survey Institute of Hebei Province,Langfang,Hebei 065000,China;Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang,Hebei 065000,China)
出处
《中国无机分析化学》
CAS
北大核心
2021年第3期36-41,共6页
Chinese Journal of Inorganic Analytical Chemistry
基金
地质大调查项目(1212011120278)。
关键词
元素活动态
金
电感耦合等离子体质谱法
active state elements
gold
inductively coupled plasma-mass spectrometry(ICP-MS)
