Assessing the extraction and quantification of amorphous silica in soils of forest and grassland ecosystems
Assessing the extraction and quantification of amorphous silica in soils of forest and grassland ecosystems
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评估森林和草原生态系统土壤中无定形二氧化硅的提取和定量
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
E. F. Kelly
中科院分区：
文献类型：
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作者：
L. Saccone;Daniel J. Conley;E. Koning;Daniela Sauer;Michael Sommer;D. Kaczorek;S. Blecker;E. F. Kelly
许多研究强调了无定形二氧化硅（ASi）池对地球大气层整体质量平衡的重要性。为了提高我们的知识，测量和量化这个池，有必要比较不同的提取剂溶解ASi在土壤中的能力，并测试方法开发的水生科学土壤系统。在这项工作中使用的方法包括三个酸提取技术（0.2 m NH 4-草酸盐，0.1 m NH 4-柠檬酸盐和0.5 m NH 4-乙酸盐）和两个碱提取技术（0.094 m Na 2CO 3和0.5 m NaOH），这是更常用的测量ASi在水生沉积物。结果表明，酸法提取的硅量比碱法提取的硅量低两个数量级。当应用于天然土壤样品时，这些提取表明酸技术仅能够提取松散结合的组分，例如吸附的Si和与Al和Fe结合在无定形基质中的Si。而Na 2CO 3或NaOH提取相同量的ASi在灰壤中，Na 2CO 3能够提取仅部分的ASi用NaOH提取在潮土中。在Na 2CO 3浸提前用0.1 m HCl预处理样品不会增加浸提的ASi量。目前的工作表明，碱性方法通常用于ASI对水生沉积物样品可以用于各种各样的土壤。
Many studies have highlighted the importance of the Amorphous Silica (ASi) pool to the overall mass balance in the biogeosphere. In order to advance our knowledge of measurements and quantification of this pool, it is necessary to compare the ability of different extractants to dissolve ASi in soils and to test methods developed in the aquatic sciences to soils systems. The methods used in this work included three acid extraction techniques (0.2 m NH4‐oxalate, 0.1 m NH4‐citrate and 0.5 m NH4‐acetate) and two alkaline extraction techniques (0.094 m Na2CO3 and 0.5 m NaOH), which are more commonly used for the measurement of ASi in aquatic sediments. Our results indicate that the amount of Si extracted from phytolith samples with the acid methods was two orders of magnitude less than the amount of extracted by alkaline extractions. When applied to natural soil samples, these extractions show that the acid techniques are only able to extract loosely‐bound components such as adsorbed Si and Si bound in amorphous matrices with Al and Fe. While Na2CO3 or NaOH extracted the same amount of ASi in Podzols, Na2CO3 was able to extract only part of the ASi extracted with NaOH in Chernozems. Pre‐treatment of the samples with 0.1 m HCl before the Na2CO3 extraction did not increase amounts of ASi extracted. The present work suggests that alkaline methods used commonly for ASi on aquatic sediment samples can be used on a wide variety of soils.