Single and sequential extractions are current and useful tools for estimating the availability of metals in soils or sediments. Many chemical extraction procedures have been proposed in the literature, making the comparison difficult. This study compares the data consistency of the potential availability given by four chemical extractions commonly found in the literature:

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two single procedures (using dilute HCl or EDTA as reactant)

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two sequential procedures (the modified standardized 3-steps procedure of the Standards, Measurements and Testing Programme (SMTP), namely BCR-extraction, and the 7-steps procedure of Leleyter and Probst (1999), namely LP-extraction).

The leaching procedures are all performed on the reference lake sediment CRM BCR-701, used as a reference to assess the accuracy of the modified standardized procedure of Rauret et al. (1999). The results show similar availabilities between HCl and EDTA single leaches for Zn, Cu, Cr and Pb and between HCl and the BCR procedures for Zn, Cu, Cr and Ni. The LP-extraction is the most aggressive of the four tested procedures (except for Pb extraction), mainly due to a better extraction of the exchangeable fraction, by a better dissolution of the acido-soluble phase and particularly to a better dissolution of the amorphous and crystalline Fe-oxides. The comparison between the four procedures reveals a major problem of Pb extraction, potentially due to the formation of lead precipitates during HCl and the LP-extractions, even if an overestimation of the lead availability by the BCR procedure cannot be excluded.

单次提取和连续提取是目前估算土壤或沉积物中金属有效性的有用工具。文献中已经提出了许多化学提取方法，使得比较困难。这项研究比较了文献中常见的四种化学提取所提供的潜在可用性的数据一致性：

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两次单一操作（使用稀盐酸或乙二胺四乙酸作为反应物）

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两个顺序程序（标准，测量和测试程序（SMTP）的修改的标准3步程序，即BCR提取，以及Leleyter和Probst（1999）的7步程序，即LP提取）。

浸出过程均在参考湖沉积物CRM BCR-701上进行，以评估Rauret等人的改良标准化过程的准确性。（1999）。结果表明，在HCl和EDTA单浸中，Zn，Cu，Cr和Pb的浸出率相似，在HCl和Zn，Cu，Cr和Ni的BCR过程中，浸出率相似。LP萃取是四种测试方法中最积极的方法（铅萃取除外），这主要是由于可交换馏分的萃取效果更好，酸溶相的溶解度更高，尤其是无定形物的溶解度更高和结晶的铁氧化物。四种方法之间的比较揭示了铅提取的主要问题，这可能是由于在HCl和LP萃取过程中形成了铅沉淀物，