高分辨电感耦合等离子体质谱(ICP-MS)法测定铁锰氧化态中57种元素

Determination of 57 Elements in Occluded Metals in Iron-manganese Oxides by High Resolution Inductively Coupled Plasma Mass Spectrometry

元素活动态分析作为深穿透地球化学的新方法,得到了广泛的应用。将ELEMENT XR型高分辨率等离子体质谱(HR-ICP-MS)法引入元素活动态的分析中,具有动态线性范围宽(10-12~1012)和灵敏度高的特点,使可同时测定的元素拓展至57种,大大提高了工作效率。根据实验结果结合响应面分析法,对HR-ICP-MS的主要仪器条件辅助气流量、雾化气流量和采样深度等进行了优化,确定了仪器的最佳测定条件;对铁锰氧化态的提取条件进行了系统研究:分别考察了提取时间、液固比、离心转速、提取液放置时间对提取效果的影响,确定了最佳提取条件,提取时间为24 h,液固比为15∶1,离心转速4000 r/min;在最优的测定条件和提取条件下,建立了HR-ICP-MS对铁锰氧化物结合相中57种元素的分析方法,得到了各元素的方法检出限和方法精密度,微量和痕量元素的方法检出限达到了10-9(ng/g),主量元素的检出限为10-6(mg/kg)水平,精密度为2.3%~32.5%,完全满足当前元素活动态的分析测试需要。

As a new method of deep-penetrating geochemistry,the analytical technique for determination of active state element can provide data support for searching for concealed ore bodies.In this method,ELEMENT XR high resolution plasma mass spectrometry(HR-ICP-MS)is introduced into the analysis of the active state elements which has powerful advantages in dynamic linear range(10-12-1012)and high sensitivity.It extends the simultaneous determination of more than 57 elements and greatly improves the working efficiency.In this study,based on the experimental results and Response Surface Methodology,we optimized the main instrumental conditions of HR-ICP-MS such as auxiliary gas flow,sample gas flow and sampling depth.Then we systematically studied the extraction conditions,and we investigated the effects of extraction time,liquid-solid ratio,centrifugal rotating speed and extracting solution storage time on the extraction efficiency.The extraction conditions were improved and the optimum extraction conditions were determined:the extraction time was 24 h,the liquid-solid ratio was 15∶1,and the centrifugal rotating speed was 4000 r/min.Finally,we established the HR-ICP-MS method for the analysis of 57 elements and obtained the detection limits and precision of each element in Occluded Metals in Iron-manganese Oxides.The detection limit of trace elements reached 10-9,and the major elements is 10-6.The precision is 2.3%-32.5%,which can meet the current requirements of analysis and determination of active state elements.