• 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

超细粉末压片法-X射线荧光光谱测定水系沉积物和土壤中的主量元素

Determination of Major Elements in Stream Sediments and Soils by X-ray Fluorescence Spectrometry Using Pressed-superfine Powder Pellets

  • 摘要: X射线荧光光谱分析中,粉末压片法是一种理想的绿色环保制样技术,操作简单、制样效率高,但由于受到粒度效应和矿物效应的影响,其测定误差在5%左右,因而限制了这种技术在常量元素检测方面的应用,目前主要应用于痕量元素的测定以及对分析精度要求不高的分析领域。本文运用行星式粉碎制样机,将水系沉积物和土壤标准物质在几分钟内粉碎至平均粒径4~5 μm左右,建立了超细粉末压片制样X射线荧光光谱测定SiO2、Al2O3、Fe2O3、CaO、MgO等主量元素的方法。该方法绝大多数主量元素的测量精密度(RSD)小于2%;检出限为0.003%~0.021%,优于熔融法的检出限(0.006%~0.081%),特别是原子序数小的钠元素,检出限改善4倍。本文针对水系沉积物和土壤研制的超细粉末压片法,由于样品粉碎至几微米,最大限度地减小了粒度效应的影响;X射线衍射分析表明制备样品的矿物成分以石英为主,矿物组成简单,矿物效应可以忽略不计。同时对测量数据加入烧失量进行归一化处理,各元素归一化的测量结果与标准值基本一致,方法准确度比常规压片法获得显著提高。

     

    Abstract: The powder pellet compression method for X-ray Fluorescence analysis is an ideal environmentally friendly sample preparation technique with the added advantages of being simple and having high efficiency. However, due to the impact of particle effects and mineral effects, its measurement error is within about 5%, which hinders the application of this technology in the detection of major elements. Powder pellet technology is mainly used in the determination of trace elements as well as the analysis field with less precision. In this study, the stream sediment and soil reference material were crushed to an average particle size about 4-5 μm within a few minutes by ultra-high-speed planetary pressure prototype. The method of ultra-fine pressed powder pellet sample to determine SiO2, Al2O3, Fe2O3, CaO, MgO and other major elements was established by using X-ray Fluorescence Spectrometry. Measurement precision (RSD) of the method for most of the major elements is less than 2%, and detection limits are 0.003%-0.021%, which is an improvement on the melting method detection limit (0.006%-0.081%), especially for small atomic sodium with four times improvement on the detection limit. The development of this ultra-fine powder compression method for stream sediment and soil, minimizes the impact of the particle size effect by crushing the sample into several microns. X-ray Diffraction analysis demonstrates that the mineral composition of river sediments and soil preparation is dominated by quartz. Therefore, the mineral composition is simple with negligible mineral effect. Measured data with added LOI normalized processing shows that normalized measurements for each element is consistent with the standard value. The accuracy of the method is a significant over the conventional pellet sampling method.

     

/

返回文章
返回