State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, China.
Environ Toxicol Chem. 2012 May;31(5):1012-8. doi: 10.1002/etc.1788. Epub 2012 Mar 23.
A passive water sampler with low-density polyethylene (LDPE) as the sorbent phase was built and field-tested for sensing freely dissolved concentrations of hydrophobic organic compounds (HOCs) in fresh and coastal water. Based on the measured LDPE-water partition coefficients (K(pew)) of 12 polycyclic aromatic hydrocarbons (PAHs) and dichlorodiphenyltrichloroethane (DDT) and its seven metabolites, the detection limits with the passive sampler containing 10-g LDPE ranged from 0.04 to 56.9 pg/L in the equilibrium sampling mode. Furthermore, the utility of the passive sampler in measuring dissolved HOC concentrations in open waters was examined through a comparison with solid-phase extraction combined with liquid-liquid extraction (SPE-LLE) and poly(dimethyl)siloxane (PDMS) coated fiber samplers. The total concentrations of PAHs (3.8-16 ng/L) obtained by the passive sampler were lower than those (87.7-115.5 ng/L) obtained through SPE-LLE. This large difference was probably attributable to slower water exchange in and out of the passive sampler as time progressed because of blockage by algae in eutrophia reservoirs and high dissolved organic carbon contents resulting in higher-than-expected PAH concentrations by SPE-LLE. Furthermore, the concentrations and compositional profiles of DDXs (sum of p,p'-DDT, p,p'-DDD, p,p'-DDE, o,p'-DDT, o,p'-DDD, o,p'-DDE, and p,p'-DDMU) at site A obtained by the passive sampler agreed with the results obtained with the PDMS-coated fibers, suggesting that the passive sampler was able to reasonably quantify dissolved HOCs in seawater.
建立了一种使用低密度聚乙烯（LDPE）作为吸附相的被动水采样器，用于感测淡水和沿海水中疏水性有机化合物（HOC）的自由溶解浓度。基于 12 种多环芳烃（PAHs）和滴滴涕（DDT）及其七种代谢物在 LDPE 与水之间的测量分配系数（K（pew）），在平衡采样模式下，含有 10 克 LDPE 的被动采样器的检测限范围为 0.04 至 56.9 pg/L。此外，通过与固相萃取结合液液萃取（SPE-LLE）和聚二甲基硅氧烷（PDMS）涂层纤维采样器的比较，检验了被动采样器在测量开阔水域中溶解 HOC 浓度方面的实用性。通过被动采样器获得的 PAHs 总浓度（3.8-16 ng/L）低于 SPE-LLE 获得的浓度（87.7-115.5 ng/L）。这种较大的差异可能归因于随着时间的推移，藻类在富营养化水库中堵塞以及高溶解有机碳含量导致被动采样器内外水交换速度变慢，从而导致 SPE-LLE 预测的 PAH 浓度高于实际浓度。此外，通过被动采样器在 A 点获得的 DDXs（p,p'-DDT、p,p'-DDD、p,p'-DDE、o,p'-DDT、o,p'-DDD、o,p'-DDE 和 p,p'-DDMU 的总和）的浓度和组成分布与 PDMS 涂层纤维的结果一致，表明被动采样器能够合理地量化海水中的溶解 HOC。
