酶联免疫法测定蔬菜中2,4-二氯苯氧乙酸的改进

Determination of 2,4-dichlorophenoxyacetic acid residue in vegetables by enzyme linked immunosorbent assay

目的研究酶联免疫吸附法快速测定茄果类蔬菜中2,4-二氯苯氧乙酸残留量(2,4-dichlorophenoxyacetic acid,2,4-D)的分析方法。方法对蔬菜的提取分离方法进行优化,捣碎后经萃取溶剂萃取后,离心去上清液吹干后经酶标仪测定茄果类蔬菜中2,4-D残留量。以水体2,4-D试剂盒,通过运用8种不同萃取溶剂对样品前处理条件进行优化,分别考察本方法的灵敏度、回收率、重复性。结果本方法的检测灵敏度为1.782μg/kg,添加浓度分别为5.9、10.0、20.0μg/kg时的回收率在74%~118%,番茄和青椒样品的重复性试验的标准偏差分别为3.5%和4.16%,使用乙酸乙酯为溶剂时,对青椒的残留2,4-D萃取效果最佳。结论本方法稳定性和重现性好,且最大检出限量均比已有研究结果大10倍以上,可广泛用于番茄及青椒等茄果类蔬菜中2,4-D残留量的检测。

Objective To study the method of enzyme-linked immunosorbent assay (ELISA) for rapid determination of 2,4-dichlorobenzene in solanaceous fruit vegetable. Methods The extraction and separation methods were optimized for vegetables after extraction by solvent extraction and centrifugation to make clear liquid and were blown dried followed by enzyme instrument determination of 2,4-D in solanaceous fruit vegetable residues. With 2,4-D kits, by using 8 different extraction solvents on sample preparation condition was optimized to investigate sensitivity, recovery, and repeatability of this method respectively. Results The detection sensitivity of this method was 1.782μg/kg, and the recovery at the adding concentrations of 5.9, 10.0, and 20.0 μg/kg was 74% ~ 118%, the sample standard deviation of the repeatability test of tomato and green pepper were 3.5%and 4.16%, respectively. Using ethyl acetate as solvent, the extraction effect of 2,4-D residue in green pepper was the best. Conclusion This method has a good stability and reproducibility, its maximum detection limit is 10 times more than the existing research results, which can be widely used in the solanaceous fruit vegetables such as tomato and green pepper for 2, 4-D residue detection.