微波等离子体原子发射光谱法测定偏远矿区海泡石中的主微量元素

海泡石是具有层状结构的含水富镁硅酸盐黏土矿物，其中无机元素含量是揭示其成矿物质来源、成矿流体性质和矿床成因的重要依据，通常采用电感耦合等离子体发射光谱/质谱法（ICP-OES/MS）进行测定，等离子体（ICP）的高温激发会产生成大量谱线干扰，维持ICP稳定工作需使用高纯氩气，持续供气对于偏远矿区海泡石的检测还将面对气体采购和运输不便的问题。本文基于微波等离子体原子发射光谱（MP-AES）的低温激发技术减少光谱干扰，建立了准确测定偏远矿区海泡石中主量元素Mg、Al、Ca、Fe、K、Na和微量元素Cu、Zn、Mn、Pb含量的分析方法。利用硝酸-盐酸-氢氟酸混合酸对海泡石进行微波消解，避免了样品处理过程中分析元素的损失，加快了样品处理速度，同时提高了样品溶液的稳定性。通过选择各元素光谱线的分析波长，并利用快速线性干扰校正（FLIC）技术校正光谱干扰，以Lu为内标元素校正基体效应，提高了灵敏度和准确度。各元素的检出限为0.19~14.6μg/L。海泡石国家标准物质（GBW07138）各元素测定值与认定值的相对误差在-5.0%~6.7%之间。本方法具有检出限低、线性范围宽、结果准确等优点；MP-AES采用自带的氮气发生器为等离子体提供氮气作为工作气，无需引入复杂气体，提高了分析效率，尤其适用于气体采购和运输不便的偏远矿区。

Determination of Major and Trace Elements in Sepiolite of Remote Mining Area by Microwave Plasma-Atomic Emission Spectroscopy

BACKGROUNDSepiolite is a layered hydrous magnesium-rich silicate clay mineral. The content of inorganic elements in sepiolite is an important basis for revealing the source of ore-forming materials, the nature of ore-forming fluids and the genesis of the deposit. It is usually determined by inductively coupled plasma-optical emission spectrometry (ICP-OES) and inductively coupled plasma-mass spectrometry (ICP-MS), high temperature excitation of inductively coupled plasma (ICP) will produce a large number of spectral interferences. High purity argon is needed to maintain the stability of ICP. Continuous gas supply for sepiolite detection in remote mining areas will also cause the problem of inconvenient gas procurement and transportation.