高分辨率等离子体质谱测定水提取相中59个元素的应用研究

摘要

金属活动态测量法是寻找隐伏矿的深穿透地球化学方法之一，目前有关金属活动态测量的应用研究较多，但对于活动态的提取和相态（包括水提取相）分析测定方法研究较少。传统的原子吸收光谱法只能测定单元素，而电感耦合等离子体质谱法（ ICP-MS ）最多同时测定水提取相中5个元素（ Cr、Cu、Zn、Cd、Pb），已不能满足当前化探任务中金属活动态测量的需要。本文建立了高分辨率电感耦合等离子体质谱（ HR-ICP-MS）测定水提取相中59个元素的方法。通过试验，确定了59个元素的最佳提取条件为：提取时间24 h，提取温度35℃，液固比15：1，固液分离方法为离心分离。方法精密度（ RSD，n=12）为3.11%~38.1%，其中RSD大于20%的数据只占全部试验结果的28.4%，表明该方法较为准确可靠，方法检出限满足元素活动态的分析要求。运用HR-ICP-MS 测定水提取相中元素的方法，不仅增加了测定元素的数量，也降低了检出限，提高了精密度，可以为勘查地球化学研究提供更为全面的信息。%The measurement for the metal active state is one of the current methods in deep-penetrating geochemistry for searching buried ores. There are much applied research concerning metal active state,but less on the extraction of active states and phase analysis ( such as the water extraction phase ). Traditional atomic absorption spectrometry can only be used to determine one element at a time,while only 5 elements( Cr,Cu,Zn, Cd and Pb)in the water extraction phase can be simultaneously measured by Inductively Coupled Plasma-Mass Spectrometry( ICP-MS). However,either method can meet the demands of metal active state measurements for current geochemical exploration. A method for the determination of 59 elements in the water extraction phase has been established by using High Resolution Inductively Coupled Plasma-Mass Spectrometry ( HR-ICP-MS ). Moreover,the optimum extraction conditions to determine these elements in the water extraction phase by experiment are:extraction time is 24 h at extraction temperature of 35℃ with liquid-solid ratio of 15 : 1 . Solid-liquid phases were separated by centrifugation. The precision(RSD,n=12)is 3. 11% -38. 1%,of which more than 20% RSD data accounted for only 28. 4% of all test results,indicating that the method is accurate and reliable,and the detection limit of this method can meet the analytical requirements of elemental active state. The method of determination of the water extraction phase elements by using HR-ICP-MS not only increases the number of target elements,but also reduces the detection limit and improves the precision,which can provide more comprehensive data for exploration geochemistry.