Studies On Quantitative Structure Activity Research Of Phenylurea Herbicides And Their Analysis Methods

Phenylurea herbicides are used widely in agriculture. Used widely and high toxicity make it necessary to monitor the concentration of phenylurea herbicides in the environment. In this paper, we studied phenylurea herbicides quantificational structure activity showed high correlations (R = 0.934) between their octanol-water partition coefficients and capacity factors, making possible the prediction of the partition behavior of untested phenylurea herbicides. The result showed the RP-HPLC method had better results than the molecular connectivity index method.In this paper, we also introduced a variety of methods for determination the phenylurea herbicides, for instance GC, LC, UV, TLC. And we studied a spectrophotometric method for the determination of fenuron, monuron and isoproturon. It was based on acidic hydrolysis of the herbicide, then followed by diazotization and coupling with chromotropic acid in alkaline medium. The λmax of the colored compound is at 510nm, 516nm and 500nm respectively, and Beer's law is valid in the range of 0-9.504mg/L,0-11.60mg/L and 0-14.7900mg/L, εis 1.8×104 L(moL-1(cm-1, 1.9×104 L(moL-1(cm-1 and 2.3777×104 L(moL-1(cm-1 respecttivly.