Institute of Environmental Science and Technology, Zhejiang University, Hangzhou 310029, People's Republic of China.
Environ Monit Assess. 2012 Jan;184(1):549-59. doi: 10.1007/s10661-011-1987-9. Epub 2011 Aug 26.
It has become apparent that the threat of an organic pollutant in soil is directly related to its bioavailable fraction and that the use of total contaminant concentrations as a measure of potential contaminant exposure to plants or soil organisms is inappropriate. In light of this, non-exhaustive extraction techniques are being investigated to assess their appropriateness in determining bioavailability. To find a suitable and rapid extraction method to predict phenanthrene bioavailability, multiple extraction techniques (i.e., mild hydroxypropyl-β-cyclodextrin (HPCD) and organic solvents extraction) were investigated in soil spiked to a range of phenanthrene levels (i.e., 1.12, 8.52, 73, 136, and 335 μg g( - 1) dry soil). The bioaccumulation of phenanthrene in earthworm (Eisenia fetida) was used as the reference system for bioavailability. Correlation results for phenanthrene suggested that mild HPCD extraction was a better method to predict bioavailability of phenanthrene in soil compared with organic solvents extraction. Aged (i.e., 150 days) and fresh (i.e., 0 day) soil samples were used to evaluate the extraction efficiency and the effect of soil contact time on the availability of phenanthrene. The percentage of phenanthrene accumulated by earthworms and percent recoveries by mild extractants changed significantly with aging time. Thus, aging significantly reduced the earthworm uptake and chemical extractability of phenanthrene. In general, among organic extractants, methanol showed recoveries comparable to those of mild HPCD for both aged and unaged soil matrices. Hence, this extractant can be suitable after HPCD to evaluate risk of contaminated soils.
显然，土壤中有机污染物的威胁与其生物可利用部分直接相关，而使用污染物总量浓度作为植物或土壤生物潜在污染物暴露的衡量标准是不恰当的。有鉴于此，人们正在研究非耗竭性提取技术，以评估其在确定生物可利用性方面的适用性。为了找到一种合适且快速的提取方法来预测菲的生物可利用性，研究了多种提取技术（即温和的羟丙基-β-环糊精（HPCD）和有机溶剂提取）在土壤中菲的浓度范围（即 1.12、8.52、73、136 和 335μg g(-1)干土）。菲在蚯蚓（赤子爱胜蚓）中的生物积累被用作生物可利用性的参考系统。菲的相关结果表明，与有机溶剂提取相比，温和 HPCD 提取是一种更好的预测土壤中菲生物可利用性的方法。使用老化（即 150 天）和新鲜（即 0 天）土壤样品来评估提取效率以及土壤接触时间对菲可用性的影响。蚯蚓积累的菲百分比和温和提取剂的回收率随着老化时间的变化而显著变化。因此，老化显著降低了蚯蚓对菲的吸收和化学可提取性。一般来说，在有机溶剂提取剂中，甲醇对老化和未老化土壤基质的回收率与温和 HPCD 相当。因此，这种提取剂可以在 HPCD 之后适用于评估污染土壤的风险。
