Liu Yihua, Wang Chunmei, Gui Wenjun, Bi Jincheng, Jin Maojun, Zhu Guonian
Institute of Pesticide and Environmental Toxicology, Zhejiang University, Hangzhou 310029, China.
Ecotoxicol Environ Saf. 2009 Sep;72(6):1673-9. doi: 10.1016/j.ecoenv.2009.04.015. Epub 2009 May 9.
A sensitive competitive indirect enzyme-linked immunosorbent assay (ELISA) for the insecticide parathion was developed. The optimal immunogen was 5-(ethoxy(4-nitrophenoxy)phosphorothioylamino)pentanoic acid. In addition, five competitors were applied for development of a heterologous competitive indirect ELISA. Then several physicochemical factors (organic solvent, ionic strength and pH) that influence assay performance were studied and optimized. The IC(50) and IC(10) of the optimized ELISA were 0.95 and 0.15 ng/mL, respectively, which meant almost 86-fold and 6-fold improvement in the assay sensitivity in comparison with the homologous assay (81.74 ng/mL) and the non-optimized heterologous assay (5.60 ng/mL). Finally, the assay was applied to the analysis of parathion in spiked agricultural and environmental samples without extraction or cleanup. The average recoveries of parathion added to water, soil, cucumber, rice and corn were between 78.57% and 107.67%. The limit of detection (LOD) for water and soil samples was 5 ng/mL, and the LOD for cucumber, rice and corn samples was 10 ng/mL.
开发了一种用于杀虫剂对硫磷的灵敏竞争性间接酶联免疫吸附测定法（ELISA）。最佳免疫原是5-（乙氧基（4-硝基苯氧基）硫代磷酰氨基）戊酸。此外，应用了五种竞争物来开发异源竞争性间接ELISA。然后研究并优化了影响测定性能的几个物理化学因素（有机溶剂、离子强度和pH值）。优化后的ELISA的IC（50）和IC（10）分别为0.95和0.15 ng/mL，这意味着与同源测定法（81.74 ng/mL）和未优化的异源测定法（5.60 ng/mL）相比，测定灵敏度分别提高了近86倍和6倍。最后，该测定法应用于加标农业和环境样品中对硫磷的分析，无需萃取或净化。添加到水、土壤、黄瓜、大米和玉米中的对硫磷的平均回收率在78.57%至107.67%之间。水和土壤样品的检测限（LOD）为5 ng/mL，黄瓜、大米和玉米样品的LOD为10 ng/mL。
