逐级提取(SEE)技术及其在沉积物和土壤元素形态研究中的应用

SEQUENTIAL EXTRACTION (SEE) TECHNOLOGY AND ITS APPLICATIONS TO SEDIMENT AND SOIL ELEMENT SPECIATION STUDIES

概述了元素形态的研究方法,介绍了SEE技术及其在沉积物、土壤元素形态研究中的应用,并就该技术在元素形态研究中的作用、实现标准化的可能性及难度、未来发展趋势等问题进行了探讨,得出了以下三点认识:(1)SEE技术是目前沉积物、土壤元素形态研究的必要手段,但其在未来元素形态研究中的作用,在很大程度上取决于技术本身的标准化和新发展以及其它形态分析方法的发展;(2)根据研究目的,系统研究不同样品的采集和预处理方法、试剂种类和浓度以及操作条件等元素形态影响因素,对现有流程进行改进或提出新的更合理的流程,作为SEE技术的标准流程,是必要且可能的,但其任务也是艰巨的;(3)SEE技术可能向两个趋势发展,分别形成微波加热-连续流-逐级提取(MCSE)技术以及微波加热-超声波震荡-动力学-平行提取(MUKPE)技术。

This article summarizes the current common research methods of element speciation, and introduces the development of sequential extraction (SEE) technology and its applications to sediment and soil element speciation studies. Focus of this review is placed on some important issues, such as the role of SEE technology in element speciation studies, probabilities and potential difficulties in standardization of the SEE technology and its future developing trends. Three conclusive points have been obtained: firstly, SEE technology is an essential tool in the current sediment and soil element speciation studies, but its future role in element speciation studies will depend not only on its own standardization and new development, but also on the development of other technologies; secondly, it will be necessary and possible but a little difficult to develop an improved procedure(s) as the standard of SEE technology by systematically studying the controlling factors of element speciation analysis, such as sampling and pretreatment methods of different sample types, concentrations of reagents, and operational conditions, according to different objectives of study; finally, it seems that SEE technology will develop in two new directions, that is, microwave heating-continuous flow-sequential extraction (MCSE) technology and microwave heating-ultrasonic vibrating-kinetic-parallel extraction (MUKPE) technology.