Nonexhaustive cyclodextrin-based extraction technique for the evaluation of PAH bioavailability
Nonexhaustive cyclodextrin-based extraction technique for the evaluation of PAH bioavailability
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DOI：
10.1021/es990946c
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发表时间：
2000-08-01
影响因子：
11.4
通讯作者：
Semple, KT
中科院分区：
文献类型：
--
作者：
Reid, BJ;Stokes, JD;Semple, KT
传统上，土壤提取技术一直关注的是在“彻底”提取后确定“总”有机污染物浓度。然而，鉴于与有机污染物可利用性和老化有关的知识越来越多，这些方法与可能构成生态风险的污染物的数量（即“生物可利用性”部分）几乎没有关系。因此，不那么详尽的技术已成为最近方法的主题，希望它们可以进入“不稳定”或生物可利用池。本文介绍了一种利用羟丙基- β -环糊精（HPCD）的水基提取技术从土壤中提取多环芳烃。从高效液相色谱浓度、萃取时间、溶液缓冲等方面对方法进行了优化。然后对该程序进行测试和验证，以一系列浓度添加到一系列土壤类型的c -14标记的多环芳烃（菲，芘和苯并[a]芘）。分解代谢活性微生物矿化土壤相关菲的量与总残留菲浓度相关(r(2) = 0.889；最佳拟合线斜率= 0.763；Intercept = -5.662；n = 24)、二氯甲烷(DCM)-可提取菲浓度（r2 = 0.986；最佳拟合线斜率= 0.648；截距= 0.340;n = 24）、丁醇(BuOH)-可提取菲浓度(r(2) = 0.957；最佳拟合线斜率= 0.614；截距= 0.544；n = 24)，高效液相色谱法可提取菲浓度(r(2) = 0.964；最佳拟合线斜率= 0.997；截距= 0.162；N = 24)。因此，在本研究中，使用优化的高效液相色谱提取技术可以最好地预测土壤相关菲的微生物生物可利用浓度。相比之下，DCM索氏提取法和BuOH摇提法对菲的生物利用度平均都高估了60%。
Traditionally, soil extraction techniques have been concerned with the determination of "total" organic contaminant concentrations, following an "exhaustive" extraction. However, in light of the increasing body of knowledge relating to organic contaminant availability and aging, such methods have little relevance to the amount of contaminant that may pose an ecological risk i.e., the "bioavailable" portion. Less exhaustive techniques have therefore been the subject of more recent approaches in the hope that they may access the "labile" or bioavailable pool. The use of an aqueous-based extraction technique utilizing hydroxypropyl-beta-cyclodextrin (HPCD) is presented here for the extraction of PAHs from soil. The optimization of the method is described in terms of HPCD concentration, extraction time, and solution buffering. The procedure is then tested and validated for a range of C-14-labeled PAHs (phenanthrene, pyrene, and benzo[a]pyrene) added at a range of concentrations to a range of soil types. The amounts of soil-associated phenanthrene mineralized by catabolically active microorganisms were correlated with total residual phenanthrene concentrations (r(2) = 0.889; slope of best fit line = 0.763; intercept = -5.662; n = 24), dichloromethane (DCM)-extractable phenanthrene concentrations (r2 = 0.986; slope of best fit line = 0.648; intercept = 0.340; n = 24), butan-1-ol (BuOH)-extractable phenanthrene concentrations (r(2) = 0.957; slope of best fit line = 0.614; intercept = 0.544; n = 24), and HPCD-extractable phenanthrene concentrations (r(2) = 0.964; slope of best fit line = 0.997; intercept = 0.162; n = 24). Th us, in this study, the microbially bioavailable concentrations of soil-associated phenanthrene were best predicted using the optimized HPCD extraction technique. In contrast, the DCM Soxhlet extraction and the BuOH shake extraction both overestimated phenanthrene bioavailability by, on average, >60%.