Research Institute for Environment, Agriculture, and Fisheries, Osaka Prefectural Government, 1-3-62 Nakamichi, Higashinari-ku, Osaka 537-0025, Japan.
Anal Chim Acta. 2010 Feb 5;659(1-2):186-93. doi: 10.1016/j.aca.2009.11.059. Epub 2009 Dec 6.
This study is the first to investigate the effect of extraction temperature (150, 175, and 200 degrees C) on the simultaneous pressurized liquid extraction (PLE) of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) from a sediment sample (certified reference material: JSAC 0431). To provide basic data that will help to determine the optimum conditions for PLE, six single solvents (toluene, dichloromethane [DCM], benzene, acetonitrile, acetone, and methanol) were used as an extraction solvent. The results obtained by PLE with each solvent were compared with those obtained by Soxhlet extraction using toluene. The efficiency of PLE for 2,3,7,8-substituted PCDDs, 2,3,7,8-substituted PCDFs, and DL-PCBs, as obtained by PLE using the solvents toluene, DCM, benzene, and acetonitrile, showed an increase with increasing extraction temperature. The recoveries of PCDDs, PCDFs, and DL-PCBs obtained by PLE using toluene were similar to or inferior to those obtained using the Soxhlet method. In contrast, their recoveries obtained by PLE using DCM, benzene, and acetonitrile were similar to or higher than those obtained using the Soxhlet method. Notably, the recoveries of PCDDs, PCDFs, and DL-PCBs using benzene at 200 degrees C were 117+/-15, 123+/-13, and 115+/-12%, respectively. When using acetone and toluene, the recoveries of tetra-hexaCDDs and tetra-hexaCDFs also increased with extraction temperature. In particular, the recoveries of 2,3,7,8-tetraCDD and 2,3,7,8-tetraCDF obtained with acetone at 200 degrees C were 181+/-21 and 167+/-14%, respectively. However, the efficiency of PLE for heptaCDDs and/or heptaCDFs was insufficient at all the tested temperatures. Furthermore, the efficiency of PLE for octaCDD and/or octaCDF showed a pronounced decrease with increasing extraction temperature, yielding recoveries of approximately 40% at 200 degrees C. We found that heptaCDF isomers were produced from authentic octaCDF during the PLE procedure with acetone at 200 degrees C, indicating that the lower recoveries of highly chlorinated DDs and/or DFs are attributable to their degradation.
这项研究首次考察了提取温度（150、175 和 200°C）对同时从沉积物标准物质（JSAC 0431）中加压液体萃取（PLE）多氯二苯并对二恶英（PCDDs）、多氯二苯并呋喃（PCDFs）和类似二恶英的多氯联苯（DL-PCBs）的影响。为了提供有助于确定 PLE 最佳条件的基本数据，使用了六种单溶剂（甲苯、二氯甲烷[DCM]、苯、乙腈、丙酮和甲醇）作为萃取溶剂。通过每种溶剂的 PLE 获得的结果与使用甲苯进行索氏提取获得的结果进行了比较。使用溶剂甲苯、DCM、苯和乙腈进行 PLE 时，2,3,7,8-取代的 PCDDs、2,3,7,8-取代的 PCDFs 和 DL-PCBs 的效率随着提取温度的升高而增加。使用甲苯进行 PLE 获得的 PCDDs、PCDFs 和 DL-PCBs 的回收率与使用索氏法获得的回收率相似或低于后者。相比之下，使用 DCM、苯和乙腈进行 PLE 获得的回收率与使用索氏法获得的回收率相似或更高。值得注意的是，使用 200°C 的苯时，PCDDs、PCDFs 和 DL-PCBs 的回收率分别为 117±15%、123±13%和 115±12%。使用丙酮和甲苯时，四-六氯二苯并二恶英和四-六氯二苯并呋喃的回收率也随萃取温度的升高而增加。特别是，使用丙酮在 200°C 下获得的 2,3,7,8-四氯二苯并二恶英和 2,3,7,8-四氯二苯并呋喃的回收率分别为 181±21%和 167±14%。然而，在所有测试温度下，PLE 对七氯二苯并二恶英和/或七氯二苯并呋喃的效率均不足。此外，随着萃取温度的升高，八氯二苯并二恶英和/或八氯二苯并呋喃的 PLE 效率明显下降，在 200°C 时的回收率约为 40%。我们发现，在 200°C 下使用丙酮进行 PLE 时，从纯八氯二苯并二恶英中生成了七氯二苯并呋喃异构体，这表明高度氯化的 DDs 和/或 DFs 的回收率较低是由于它们的降解所致。
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