直接竞争ELISA法测定土壤中异丙隆残留

Development of an Direct Competitive ELISA for the Determination of Isoproturon Residue in Soil

通过活性酯法将半抗原[1-(3-丙基羧基)-3-(4-异丙基苯基)-1-甲基脲]与辣根过氧化物酶(HRP)偶联制备酶标抗原。根据紫外扫描谱图可知酶标抗原的结合比为7.35∶1。直接竞争ELISA法测定异丙隆标准抑制曲线的线性范围为4.28～276.99μg/L,免疫反应的IC50值为39.74μg/L。对6种取代脲类除草剂的交叉反应率分别为0.48%、0.92%、0.32%、0.83%、0.31%、0.27%。土壤中异丙隆的加标回收率为96.75%～101.26%,变异系数为1.39%～3.02%。

The hapten, 1-（3-carboxypropyl）-3-（4-isopropylphenyl） -1-methylurea, was attached to HRP using N-hydroxysuccinimide reaction. The conjugation molar ratio of the hapten to HRP was 7.35：1, calculated by a UV spectrophotometry. The conjugate of hapten-HRP was used as the enzymatic antigen in the direct competitive ELISA for isoproturon was developed. The concentration of isoproturon that inhibits 50% of antibody-antigen binding （IC50） was 39.74 μg/L. The linear range of the calibration curve was 4.28-276.99 μg/L. The cross-reactivities of other six urea herbicides were 0.48%, 0.92%, 0.32%, 0.83%, 0.31% and 0.27%, respectively. The recoveries of isoproturon from the spiked soil were 96.75-101.26%, with the coefficients of variation 1.39-3.02%.