Liu Weiping, Gan Jay J, Lee Sangjin, Kabashima John N
Department of Environmental Sciences, University of California, Riverside, California 92521-0424, USA.
Environ Toxicol Chem. 2004 Jan;23(1):7-11. doi: 10.1897/03-183.
Synthetic pyrethroids (SPs) are a group of hydrophobic compounds with significant aquatic toxicity. Their strong affinity to suspended solids and humic materials suggests that SPs in natural surface water are distributed in solid-adsorbed, dissolved organic matter (DOM)-adsorbed, and freely dissolved phases. The freely dissolved phase is of particular importance because of its mobility and bioavailability. In the present study, we used solid-phase microextraction to detect the freely dissolved phase, and we evaluated the phase distribution of bifenthrin and permethrin in stream and runoff waters. In stream water, most SPs were associated with the suspended solids and, to a lesser extent, with DOM. The freely dissolved phase contributed only 0.4% to 1.0%. In runoff effluents, the freely dissolved concentration was 10% to 27% of the overall concentration. The predominant partitioning into the adsorbed phases implies that the toxicity of SPs in surface water is reduced because of decreased bioavailability. This also suggests that monitoring protocols that do not selectively define the freely dissolved phase can lead to significant overestimation of toxicity or water-quality impacts by SPs.
合成拟除虫菊酯（SPs）是一类具有显著水生毒性的疏水性化合物。它们对悬浮固体和腐殖质具有很强的亲和力，这表明天然地表水中的SPs分布在固体吸附相、溶解有机物（DOM）吸附相和自由溶解相中。自由溶解相因其流动性和生物可利用性而尤为重要。在本研究中，我们使用固相微萃取来检测自由溶解相，并评估联苯菊酯和氯菊酯在溪流和径流水中的相分布。在溪水中，大多数SPs与悬浮固体相关，在较小程度上与DOM相关。自由溶解相仅占0.4%至1.0%。在径流废水中，自由溶解浓度占总浓度的10%至27%。主要分配到吸附相中意味着地表水中SPs的毒性因生物可利用性降低而降低。这也表明，未选择性定义自由溶解相的监测方案可能导致对SPs毒性或水质影响的显著高估。
