四氟醚唑在草莓和土壤中的残留动态研究

研究了杀菌剂四氟醚唑的残留分析方法及其在草莓和土壤中的消解动态和最终残留量。草莓经丙酮提取抽滤后,加入饱和醋酸铅和氯化钠水溶液利用共沉淀法除去杂质,再经液液分配及活性炭柱净化、浓缩、定容后,用带ECD检测器的气相色谱进行测定。四氟醚唑的最低检出量为0.03 ng,在草莓和土壤中的最低检出浓度均为0.02 mg/kg,在草莓和土壤中的平均回收率为95.9% ~97.5%,变异系数1.5% ~2.8%,符合残留分析要求。用该方法测定了四氟醚唑在草莓和土壤中的消解动态以及最终残留量,结果表明:四氟醚唑在草莓上的降解速度较快,半衰期为4.2 d;在土壤中降解速度稍慢,半衰期为15.4 d,施药后7 d四氟醚唑的消解达到80%以上。

Study on Residue Dynamics of Tetraconazole in Strawberry and Soil

A method was developed to determine residue of tetraconazole in strawberry and soil, the degradation and final residue of tetraconazole were studied also. Residues of tetraconazole were extracted from strawberry and soil with acetone, purified by precipitation, liquid-liquid partition and active carbon, concentrated and determined by GC-ECD. The lowest detection limit of instrument for tetraconazole was 3.0×10^-11 g. The limit of quantification was 0.02 mg/kg. The average recovery and coefficient of variation of this method were 95.9% ~97.5% and 1.5% ~2.8%, respectively. The degradation and final residue of tetraconazole were determined with the method as mentioned. The results showed that half-life of tetraconazole was 4.2 d in strawberry and 15.4 d in soil, respectively. degradation rate of tetraconazole in strawberry amounted to about 80% on the 7th day after the application.