Purpose

For the sake of risk assessment for arsenic-contaminated sites, the purpose of this study is to estimate the bioavailable arsenic fractions in soil by using the three arsenic-specific sequential extraction procedures (SEPs) and distinguish which SEP can reliably identify and estimate the bioavailable arsenic, so as to screen the most suitable SEP for the risk assessment of arsenic-contaminated sites.

Materials and methods

The arsenic uptake by spinach and amaranth was used to evaluate bioavailability of arsenic fractions defined by the SEPs proposed by Shiowatana, Larios, and Wenzel, respectively, as well as the ability of these three SEPs to identify and estimate bioavailable arsenic.

Results and discussion

The results showed that besides the highly mobile arsenic fractions defined by each SEP, the less mobile HCl-extractable arsenic (mainly carbonate-bound arsenic) in Shiowatana SEP was also the source of bioavailable arsenic, and their contribution to bioavailable arsenic depended not only on their mobility but also on their content, suggesting that the independent extraction of carbonate-bound arsenic should be considered in the design of arsenic-specific SEPs.

Conclusions

All three SEPs could provide approximate estimation of bioavailable arsenic fractions. Although Wenzel SEP performed slightly worse than Larios SEP and Shiowatana SEP, all three SEPs had acceptable accuracy and reproducibility in arsenic fractionation. However, the Shiowatana SEP performed more comprehensive in extracting potential bioavailable arsenic fractions and identifying the source of bioavailable arsenic, indicating that it might be more suitable for the risk assessment of arsenic-polluted sites based on arsenic fractionation.

中文翻译：

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比较不同顺序提取程序以鉴定和估算土壤中砷组分的生物利用度

目的

为了对砷污染的地点进行风险评估，本研究的目的是通过使用三种特定于砷的顺序提取程序（SEP）估算土壤中生物可利用的砷组分，并区分哪种SEP能够可靠地识别和估算生物利用度砷，以便筛选出最合适的SEP进行砷污染场所的风险评估。

材料和方法

菠菜和a菜对砷的吸收分别用于评估Shiowatana，Larios和Wenzel分别提出的SEP所定义的砷馏分的生物利用度，以及这三种SEP识别和评估生物利用砷的能力。

结果和讨论

结果表明，除了每个SEP所定义的高移动性砷组分外，盐沼中SEP中移动性较弱的HCl可萃取的HCl（主要是碳酸盐结合的砷）也是生物可利用的砷的来源，它们对生物可利用的砷的贡献不仅取决于它们的流动性以及含量上的差异，表明在设计特定于砷的SEP时应考虑独立提取与碳酸盐结合的砷。

结论

所有三个SEP都可以提供生物可利用砷含量的近似估算。尽管Wenzel SEP的性能比Larios SEP和Shiowatana SEP稍差，但所有三种SEP在砷分离方面均具有可接受的准确性和可重复性。但是，Shiowatana SEP在提取潜在的生物可利用的砷馏分和确定生物可利用的砷的来源方面表现得更为全面，这表明它可能更适合基于砷分级的砷污染地点的风险评估。