Fisheries and Illinois Aquaculture Center and Department of Zoology, Southern Illinois University, 171 Life Science II, Carbondale, IL 62901, USA.
Arch Environ Contam Toxicol. 2010 Feb;58(2):255-67. doi: 10.1007/s00244-009-9398-4. Epub 2009 Oct 2.
Pyrethroid insecticides have been implicated as the cause of sediment toxicity to Hyalella azteca in both agricultural and urban areas of California; however, for a subset of these toxic sediments (approximately 30%), the cause of toxicity remains unidentified. This article describes the analytical method development for seven additional pesticides that are being examined to determine if they might play a role in the unexplained toxicity. A pressurized liquid extraction method was optimized to simultaneously extract diazinon, methyl parathion, oxyfluorfen, dicofol, fenpropathrin, pyraclostrobin, and indoxacarb from sediment, and the extracts were cleaned using a two-step solid-phase extraction procedure. The final extract was analyzed for the target pesticides by gas chromatography/nitrogen-phosphorus detector (GC/NPD), and gas chromatography/electron capture detector (GC/ECD), after sulfur was removed by shaking with copper and cold crystallization. Three sediments were used as reference matrices to assess method accuracy and precision. Method detection limits were 0.23-1.8 ng/g dry sediment using seven replicates of sediment spiked at 1.0 ng/g dry sediment. Recoveries ranged from 61.6 to 118% with relative standard deviations of 2.1-17% when spiked at 5.0 and 50 ng/g dry sediment. The three reference sediments, spiked with 50 ng/g dry weight of the pesticide mixture, were aged for 0.25, 1, 4, 7, and 14 days. Recoveries of the pesticides in the sediments generally decreased with increased aging time, but the magnitude of the decline was pesticide and sediment dependent. The developed method was applied to field-collected sediments from the Central Valley of California.
拟除虫菊酯杀虫剂已被认为是加利福尼亚州农业和城市地区中 Hyalella azteca 底泥毒性的原因；然而，对于这些有毒底泥中的一部分（约 30%），其毒性原因仍未确定。本文描述了七种额外杀虫剂的分析方法开发，这些杀虫剂正在被检测，以确定它们是否可能在未解释的毒性中发挥作用。优化了加压液体提取方法，以同时从底泥中提取二嗪磷、甲基对硫磷、乙氧氟草醚、三氯杀螨醇、甲氰菊酯、吡唑醚菌酯和茚虫威，并使用两步固相萃取程序对提取物进行净化。通过与铜摇荡和低温结晶除去硫后，用气相色谱/氮磷检测器（GC/NPD）和气相色谱/电子捕获检测器（GC/ECD）分析最终提取物中的目标杀虫剂。使用三种底泥作为参考基质来评估方法的准确性和精密度。使用七种 1.0ng/g 干底泥加标沉积物重复样，方法检测限为 0.23-1.8ng/g 干底泥。当以 5.0 和 50ng/g 干底泥加标时，回收率范围为 61.6-118%，相对标准偏差为 2.1-17%。将三种参考底泥以 50ng/g 干重的农药混合物加标，老化 0.25、1、4、7 和 14 天。底泥中农药的回收率通常随老化时间的增加而降低，但下降幅度取决于农药和底泥。所开发的方法已应用于加利福尼亚中央山谷的实地采集的底泥。
