摘要
目前硒(Se)的测定主要采用氢化物-原子荧光光谱法(HG-AFS)。实验发现采用氢气发生器为HG-AFS提供氢气(H2),可以提高间断氢化物发生-原子荧光光谱法测定Se的灵敏度。当H2流量达到80 mL·min^-1及以上时,氢气发生器提供的H2可以先行点燃氢火焰,有效避免了点火提前或迟滞对测定的影响,提高了测定的精密度。地球化学调查通常需要测定几十种元素,需要分别进行多次消解。其中Se采用硝酸(HNO3)-高氯酸(HClO4)进行消解,消解后的样品采用浓盐酸(HCl)将Se(Ⅵ)还原为Se(Ⅳ)。而DZ/T 0279.3—2016电感耦合等离子体质谱法(ICP-MS)测定钡(Ba)、铍(Be)、铋(Bi)等15元素采用HNO3-HF-HClO4进行消解,消解后的样品采用王水溶解。实验发现地球化学样品中Se采用HNO3-氢氟酸(HF)-HClO4消解更加完全,消解后的样品采用王水溶解时,王水中含有的大量的氯离子(Cl^-)可以将Se(Ⅵ)还原为Se(Ⅳ)。因此HG-AFS测定Se和ICP-MS测定Ba, Be和Bi等15元素仅需一次消解,便可以分别进行测定。基于以上研究建立的外供H2-HG-AFS测定地球化学样品中的Se的方法,检出限达到了0.007 mg·kg^-1,精密度(n=12)在2.1%~5.3%之间。选取36个土壤和水系沉积物标准物质按照制定的方法进行测定,相对误差在-13.6%~16.9%,绝大部分误差在±10%以内,取得了非常满意的效果。
At present, the detection of selenium(Se) is mainly carried out by hydride generation-atomic fluorescence spectroscopy(HG-AFS). It has been found that the sensitivity of Se can be improved by using the interval hydrogen generator to provide the hydrogen(H2) for HG-AFS. When the H2 flow rate reaches 80 mL·min^-1 and above, the H2 provided by the hydrogen generator can ignite the hydrogen flame first, effectively avoiding the influence of ignition early or delay on the measurement, which can improve the precision of the measurement. In geochemical surveys, dozens of elements need to be detection, and they also needs to perform multiple digestions separately. Se, as one of the elements, is digested with nitric acid(HNO3)-perchloric acid(HClO4), after the digestion, Se(Ⅵ) will be reduced to Se(Ⅳ) by concentrated hydrochloric acid(HCl). According to DZ/T 0279.3—2016, when using inductively coupled plasma mass spectrometry(ICP-MS) to determine 15 elements such as barium(Ba), beryllium(Be) and bismuth(Bi), the samples are digested with HNO3-HF-HClO4 and then dissolved in aqua regia. It was found that Se in geochemical samples is more completely digested with HNO3-HF-HClO4, and at large number of chloride ions(Cl^-) contained in aqua regia can reduce Se(Ⅵ) to Se(Ⅳ). Therefore, only one digestion is needed and then detect Se by HG-AFS as well as other 15 elements using ICP-MS separately. Based on the above research results, this method for determining Se in geochemical samples by H2-HG-AFS has a detection limit of 0.007 mg·kg^-1, and a precision(n=12) of 2.1% to 5.3%. According to the established method, 36 soil and water sediment standard materials were selected to analysis, the relative error was between-13.61% to 16.9%, and most of the errors were within ±10%, which achieved very satisfactory results.
作者
陈海杰
马娜
白金峰
陈大磊
顾雪
于兆水
孙彬彬
张勤
CHEN Hai-jie;MA Na;BAI Jin-feng;CHEN Da-lei;GU Xue;YU Zhao-shui;SUN Bin-bin;ZHANG Qin(Key Laboratory of Geochemical Exploration,Ministry of Natural Resources,Langfang 065000,China;Institute of Geophysical and Geochemical Exploration,Chinese Academy of Geological Sciences,Langfang 065000,China;Shandong Institute of Geophysical&Geochemical Exploration,Ji’nan 250013,China)
出处
《光谱学与光谱分析》
SCIE
EI
CAS
CSCD
北大核心
2020年第9期2896-2900,共5页
Spectroscopy and Spectral Analysis
基金
国家重点研发计划课题(2016YFC0600601)
地质调查项目(DD20190518,DD20190522)
物化探所中央级公益性科研院所基本科研业务费专项(AS2016J13)资助。
关键词
外供氢气
硒
氢化物
原子荧光光谱法
External supply H2
Selenium
Hydride generation
Atomic fluorescence spectroscopy
