Of Three Phenylurea Herbicides High Performance Liquid Chromatography Analysis Methods And Their Environmental Behavior

With the use of a lot of pesticides, there was harm to human being's health and the environment in the world. Phenylurea herbicides were the common herbicides in our country. They were persistent in the soil a quarter of a year and highly carcinomatous. Therefore, the analysis into their persistence in the water and the soil were of great importance.Solid phase extraction (SPE), as a sample pretreatment technique was developed in the recent years. It had the advantage of analytical speed, simplicity, low costs, safety, no emulsification, flexibility and high preconcentration factor, and was used to separate and preconcentrate lots of organic analytes.This article totally described the development, principle, performing procedure, devices and the factors influencing process and recovery of SPE. Its applications in environmental analysis were also well reviewed. Furthermore, the detection methods and its trend were summarized. Finally the new techniques of solid phase extraction were outlined.The main conclusions were as follows:1. The best chromatographic conditions were UV detection wavelength of 250nm, mobile phase of methanol/water at 60/40(v/v), mobile phase flow rate of 0.7mL/min, column temperature of 35 , the column used was ODS, were used to determine the phenylurea herbicides in the environment.2. C18 was selected as the best solid phase for extracting trace phenylurea herbicides in water samples. In addition, most of the influencing factors were studied and optimized. The result showed that tetrahydrofuran was the preferred elution solvents for the absorbed phenylurea herbicides. When the elution solvent (1.5mL) was selected, the variation of recoveries as a function of the volume of elution solvent used can be determined. The addition of l%methanol into the sample prior to spiking could greatly improve the recoveries. The flow rate of sampleloading was 5mL/min. The acid of samples had no influence on the recoveries. Meanwhile, the concentration of potassium chloride in the water was 10 g/L. What's more; these were discussed in the theory.3. The degradation of the three phenylurea herbicides was investigated in the water. The results showed that hydrolysis of these three phenylurea herbicides depended on both pH and the temperature. The rate of photo degradation in the water under sunlight was very slow, when acetone was added, the rate was fast. However, the rate of photo degradation was much faster than those, when it was under UV lamp, only several hours.4. Research on the adsorption of the three phenylurea herbicides in four different types of soil in Changchun region showed that the content of organic carbon was the major factor of adsorption in the soil. From the organic carbon adsorption constant, linuron had middling transference, diuron and monuron had upper transference, and these showed that they had worse transference in the soil.5. In the analysis of real samples such as surface run-off water, Solid phase extraction technique enabled the elimination of matrix interference and the work was possible.