Studies On The Residue Analysis And Residual Dynamics Of Metribuzin And Other Pesticides

The hazards of pesticide residues to human health and environment have caught many attentions through out of the world. To evaluate the risk of pesticide residues, the analytical method for determine residues of metribuzin, pyribambenz-propyl, mesosulfuron-methyl, fluquinconazole, pyrimethanil and fipronil in crops and soils were developed, and their residue dynamics in crops and soil environment were studied in this paper. The molecularly imprinted polymer (MIP) of metribuzin was prepared by in-situ polymerization. The retention behavior of metribuzin and its structural analogs were determined on both the MIP and blank columns. The results showed that the MIP had high affinity and selectivity for metribuzin. This monolithic polymer was used for on-line preconcentration and detection of metribuzin residue in soil samples. The dynamics and final state of residues of metribuzin in corn and soil were studied. The guideline for safety application of metribuzin and the maximum residue limit (MRL) of metribuzin in corn grain were proposed based on the research results. Pyribambenz-propyl was a new herbicide with China's independent intellectual property rights. There was no related residue data and residue analysis method of pyribambenz-propyl in the world before. The HPLC-UV detection which was used to determine pyribambenz-propyl residues in rapes and soil was developed. The method was easy to operate, and its accuracy and precision met the requirements of pesticide residue determination. Systematic study on pyribambenz-propyl residue degradation in rapes and soil was carried out. The guideline for safety application of pyribambenz-propyl and the MRL of pyribambenz-propyl in rapeseeds were proposed. Moreover, this paper studied and improved the analysis methods for determination of residues of mesosulfuron-methyl, fluquinconazole, pyrimethanil and fipronil. Mesosulfuron-methyl residue was detectded by HPLC, and the cost of the determination was reduced. The residues of fluquinconazole and pyrimethanil were extracted with one procedure, and the sample pretreatment had been simplified and optimized The data of these methods validation indicated that they could meet the requirements of pesticide residue determination. The residues dynamics of these pesticides in crops and soils were studied. Their dynamic equations and half lives were obtained. Suggestions about safety application of these pesticides and the MRL of these pesticides in crops were put forward based on the results.