间接竞争ELISA法测定稻田土壤中除草剂毒莠定的残留量

Development of indirect ELISA for the determination of herbicide picloram residue in paddy soils

通过对反应体系中酶标二抗（辣根过氧化物酶标记羊抗兔IgG）和抗体的最佳稀释浓度等条件的筛选和确定,最终建立了一种快速灵敏地测定污染稻田土壤中毒莠定残留量的方法--间接竞争ELISA分析方法.结果表明,酶标二抗和抗体的最佳稀释度均为1：500（体积比）,毒莠定的检出下限达到5 ng·mL^-1,在0.07～0.7μg·mL^-1浓度范围内有良好的线性;土壤浸出液加样的平均回收率为104.11%,变异系数在3.13%～11.13%之间,符合农药残留分析的要求;样品基质对检测结果没有干扰.

After optimizing the concentrations of the goat-anti-rabbit IgG labeled by HRP and polyclonal rabbit-anti-picloram antibodies （PAb）, a rapid and sensitive indirect competitive ELISA was established for quantification of herbicide picloram in contaminated paddy soil samples. The results showed that the optimal dilution ratio of PAb and the goat-anti-rabbit IgG were both 1：500. The detection limit for picloram by this method （LOD） was 5 ng· mL^-1, and the linear detection range was 0.07 - 0.7 μg·mL ^-1. In the recovery assay in paddy soil extract samples, the average recovery rate was 104. 11%, and the coefficients of variation were between 3. 13% - 11. 13% , which met the requirements of pesticide residue analysis. No significant interference from the soil matrix was observed.