Plant and Soil Science Laboratory, Department of Agriculture and Ecology, Faculty of Life Sciences, University of Copenhagen, Thorvaldsensvej 40, DK-1871 Frederiksberg C, Denmark.
Plant Methods. 2009 Sep 26;5:12. doi: 10.1186/1746-4811-5-12.
Quantitative multi-elemental analysis by inductively coupled plasma (ICP) spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data.
We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight). A commercially available 64-position rotor with 5 ml disposable glass vials, originally designed for microwave-based parallel organic synthesis, was used as a platform for the digestion. The novel micro-scaled method was successfully validated by the use of various certified reference materials (CRM) with matrices rich in starch, lipid or protein. When the micro-scaled digestion procedure was applied on single rice grains or small batches of Arabidopsis seeds (1 mg, corresponding to approximately 50 seeds), the obtained elemental profiles closely matched those obtained by conventional analysis using digestion in large volume vessels. Accumulated elemental contents derived from separate analyses of rice grain fractions (aleurone, embryo and endosperm) closely matched the total content obtained by analysis of the whole rice grain.
A high-throughput micro-scaled method has been developed which enables digestion of small quantities of plant samples for subsequent elemental profiling by ICP-spectrometry. The method constitutes a valuable tool for screening of mutants and transformants. In addition, the method facilitates studies of the distribution of essential trace elements between and within plant organs which is relevant for, e.g., breeding programmes aiming at improvement of the micronutrient density in edible plant parts. Compared to existing vial-in-vial systems, the new method developed here represents a significant methodological advancement in terms of higher capacity, reduced labour consumption, lower material costs, less contamination and, as a consequence, improved analytical accuracy following micro-scaled digestion of plant samples.
电感耦合等离子体（ICP）光谱法的定量多元素分析依赖于固体样品的完全消解。然而，快速而彻底的样品消解是一项具有挑战性的分析任务，这是现代多元素分析的一个瓶颈。此外，样品数量有限，元素浓度较低。在这种情况下，需要在最小稀释和污染的情况下用小体积进行消解，以获得高精度的数据。
我们开发了一种微尺度微波消解程序，并对其进行了优化，以准确分析植物材料（1-20 毫克干重）的元素分布。一种商业上可获得的、带有 5 毫升一次性玻璃小瓶的 64 位转子，最初设计用于基于微波的平行有机合成，被用作消解的平台。该新型微尺度方法已成功应用于各种富含淀粉、脂质或蛋白质的基质的标准参考物质（CRM），并对其进行了验证。当将微尺度消解程序应用于单个米粒或小批量拟南芥种子（1 毫克，相当于约 50 粒种子）时，所获得的元素分布与通过大体积容器消解进行常规分析获得的元素分布非常吻合。从水稻籽粒各部分（糊粉层、胚和胚乳）的单独分析中得出的累积元素含量与通过整个水稻籽粒分析得出的总含量非常吻合。
开发了一种高通量的微尺度方法，可用于消解小量的植物样品，然后通过 ICP 光谱法进行元素分析。该方法为筛选突变体和转化体提供了一种有价值的工具。此外，该方法还促进了必需微量元素在植物器官之间和内部的分布研究，这对于例如旨在提高可食用植物部分的微量元素密度的育种计划具有重要意义。与现有的小瓶对小瓶系统相比，本研究开发的新方法在更高的容量、减少劳动力消耗、降低材料成本、减少污染以及因此提高植物样品微尺度消解后的分析精度方面具有显著的方法学优势。
