• 中文核心期刊
  • 中国科技核心期刊
  • CSCD来源期刊
  • DOAJ 收录
  • Scopus 收录

植物样品中无机元素分析的样品前处理方法和测定技术

Review on Sample Pretreatment Methods and Determination Techniques for Inorganic Elements in Plant Samples

  • 摘要: 植物样品中无机元素的分析测定在环境地球化学和生物地球化学的研究中起着重要作用。植物样品中元素含量一般较低,须选用科学合理的前处理技术和灵敏度高、精密度好、检出限低的测定方法。本文针对植物样品前处理方法和无机元素分析测定技术的研究进展、优势与不足进行评述。前处理方法主要根据样品和待测元素的性质进行选择:干法灰化所用试剂少、空白值低,但组织致密型的样品不易灰化完全、高温下易造成元素挥发损失;湿法消解样品消解较为完全,但试剂消耗大、空白值高、操作繁琐;微波消解可以防止部分易挥发元素损失,用酸量少、消解速度快,但称样量相对较小,不适于需要大称样量的样品分析。几乎所有针对元素分析的仪器分析技术都可以用于植物样品分析,主要根据仪器适用的元素、必要的干扰校正以及基体改进等方面进行选择:电感耦合等离子体质谱法可同时测定植物样品中40种以上的元素,高分辨质谱的检出限可达fg/mL;电感耦合等离子体发射光谱法适用于某些植物样品中含量较高的P、K、Na等元素的测定;原子吸收光谱法可分析元素达70余种,是普及程度最高的仪器分析技术之一;原子荧光光谱法与氢化物发生技术的联用,在元素含量较低的植物样品分析中技术优势更加明显;新兴的激光诱导击穿光谱技术已被应用于植物样品分析,无需复杂的样品前处理,操作简单快速,可实现原位、在线、实时、多元素同时检测;其他选择性强、灵敏度高的分析技术,满足了一些特定元素不能用常规分析技术测定的需求。当前主流分析技术的样品前处理方法都存在着缺陷,固体进样技术将成为植物样品分析领域的发展方向之一。

     

    Abstract: The determination of inorganic elements in plant samples is very important for the research of environmental geochemistry and biogeochemistry. The content of elements in plant samples is characteristically low, deeming it necessary for the determination technique to be highly sensitive, with excellent precision and an as-low-as-possible detection limit. A comparison of the current pretreatment methods for plant samples is described in this paper, namely, dry ashing, wet digestion, and microwave digestion. Pretreatment method is selected based on the characteristics of samples and target elements. The advantage of dry ashing is less consumption of reagent and low level blank, but is unsuitable for compact-tissue samples and some volatile elements. Wet digestion is a complete digestion method for most samples, but its disadvantages of high consumption of reagent, high level blank and complex procedure. Microwave digestion can avoid loss of some volatile elements with less reagent and rapid digestion, but it is unsuitable for large weighing samples. At present, most instrument techniques are suitable for plant sample analysis, based on the target element, interference correction method and matrix modification method. More than 40 elements can be determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS), and the detection limit of high resolution ICP-MS is fg/mL level. Inductively Coupled Plasma-Atomic Emission Spectrometry is suitable for determination of high content elements such as P, K and Na in plant samples. Atomic Absorption Spectrometry can determine more than 70 elements, and is one of the most popular techniques. The hydride generation technique coupled with Atomic Fluorescence Spectrometry is widely used for low content elements in plant sample. The new technique, Laser-induced Breakdown Spectroscopy, is also used for plant sample without complex pretreatment, can on-line and on-site simultaneously determine multi-elements with simple and fast operation. Other high selective and sensitive techniques are also vital to determine unusual inorganic elements in plant sample. Based on the previous research, it pointed out that the solid sampling technique is a new development trend for inorganic element analysis in plant sample.

     

/

返回文章
返回