湖泊沉积物微量元素ICP-AES与XRF分析方法和相关性研究

Study on Trace Elements of Lake Sediments by ICP-AES and XRF Core Scanning

首次以托素湖沉积物为研究对象,ICP-AES法测定沉积物微量元素Cd,Cr,Cu,Zn和Pb的含量,不同的消解法研究和优化结果确定了一个最适合托素湖沉积物前处理的体系为:5∶5∶5∶1∶1的HCl-HNO3-HF-HClO4-H2O2体系。同时与定性的XRF岩芯扫描法对托素湖沉积物微量元素进行分析,以及用含水量校正的方法,讨论了含水量对扫描方法的影响。数据比较表明,与背景值相对比,托素湖沉积物中的微量元素Cd和Zn含量偏高,Cr,Cu和Pb的含量均在背景值范围内,而XRF岩芯扫描主要受沉积物元素的控制,在一定程度上也受到沉积物中含水量的影响,两种方法测量结果有显著的正相关关系(r为0.673～0.925),具有很好的可比性。

It is the first time to study sediment of Toson lake in Qaidam Basin. Trace elements including Cd, Cr, Cu, Zn and Pb in lake sediment were measured by ICP-AES method, studied and optimized from different resolution methods respectively, and finally determined a optimum pretreatment system for sediment of Toson lake, namely, HC1-HNO3-HF-HC104-H2O2 system in the proportions of 5 .：5 .： 5 .： 1 ： 1 was determined. At the same time, the data measured by XRF core scanning were compared, the use of moisture content correction method was analyzed, and the influence of the moisture content on the scanning method was discussed. The results showed that, compared to the background value, the contents of Cd and Zn were a little higher, the content of Cr, Cu and Pb was within the background value limits. XRF core scanning was controlled by sediment elements as well as water content in sediment to some extent. The results by the two methods showed a significant positive correlation, with the correlation coefficient up to 0. 673-0. 925, and they have a great comparability.