Abstract：
Chlorpyrifos is widely used across the world as an organophosphate insecticide and frequently contaminates freshwater bodies through runoff from agricultural fields. In the laboratory, static bioassays were undertaken to examine differences in acute toxicity caused by exposure to the technical grade (94% a.i.) and an emulsifiable concentrate (20% EC) of chlorpyrifos to two species of freshwater fish, Labeo rohita and Mystus vittatus. The recovery of actual chlorpyrifos concentrations varied from 83% (technical grade, T) to 89% (emulsifiable concentrate, F) after two hours in water. The susceptibilities of the two fish species to the two types of chlorpyrifos varied. The 96-h LC50 values for T and F chlorpyrifos in L. rohita were 68 and 36 µg/L, respectively, and 120 and 62 µg/L in M. vittatus, respectively. As the exposure period was extended, the LC50 values gradually decreased. LC50 values between the technical grade and formulation were compared following the criteria of Mayer et al. (1986), Schmuck et al. (1994), APHA (1995), and Demetrio et al. (2014). It was concluded from the study that the emulsifiable concentrate (20% EC) of chlorpyrifos was more toxic than technical-grade chlorpyrifos.
摘要：
毒死蜱在世界各地被广泛用作有机磷酸盐杀虫剂，并经常通过农田径流污染淡水体。在实验室里,进行了静态生物测定，以检查由暴露于技术级（94％的a.i.）和可乳化浓缩物（20％EC）的毒死rif对两种淡水鱼引起的急性毒性差异，LabeoRohita和Mystusvittatus.实际毒死蜱浓度的回收率从83%(技术级，T)至89%(乳油，F)在水中两小时后。两种鱼类对两种毒死rif的敏感性各不相同。L.rohita中T和F毒死蜱的96小时LC50值分别为68和36µg/L，分别,和120微克/升和62微克/升，分别。随着暴露期的延长,LC50值逐渐降低。按照Mayer等人的标准比较技术等级和配方之间的LC50值。(1986),Schmucketal.(1994),APHA(1995),和Demetrio等人。(2014)。从研究中得出结论，毒死rif的可乳化浓缩物（20％EC）比工业级毒死rif的毒性更大。
