Radiolytic Effects And Products Of Endosulfan And Bifenthrin Degradation By γ-Ray

Pesticide residues have been focused on daily. Ray irradiation, a new technology without any pollution for the degradation of pesticide residues, has been gradually applied in the food industry. As one of the typical organchlorine pesticides and the pyrethroid pesticides, endosulfan and bifenthrin were chosen as experimental materials. The degradation effects, patterns and products of endosulfan and bifenthrin by gamma ray irradiation were studied. The effects of irradiated dose, interval time, and water content and ingredients of tea on the degradation of endosulfan and bifenthrin were also researched. The main projects and research results are as follows:1. The degradation rates of endosulfan and bifenthrin were at a different degree by gamma ray irradiation. The results showed that under the dose of lOkGy and the concentration of1.0mg/L, the degradation rate of endosulfan was45.5%, while under the dose of lOkGy and the concentration of5.0mg/L, the degradation rate of bifenthrin was74.8%.2. The degradation of endosulfan and bifenthrin under gamma ray irradiation were studied. Initial concentration and absorbed dose can also effect the degradation of pesticide residue. The higher the absorbed dose was, the better the removal effect of pesticide residue was. For endosulfan, the lower the initial concentration was, the higher degradation rate was. For bifenthrin, the medium concentration can raise the degradation rate.3. The main irradiation degradation products of endosulfan and bifenthrin were systematic studied and their toxicities were evaluated. Four main radiolysis products of endosulfan and bifenthrin are determined respectively by gas chromatography tandem mass spectrometry (GC/MS) analysis method. Two of radiolysis products of endosulfan are the same with the former research. The toxicities of them were evaluated by retrieving information from the toxicological databases and analyzing the structures of them. We guess that the toxicities of radiolysis products did not increase.4. The irradiated degradation rates of endosulfan and bifenthrin were influenced by discontinuous irradiation and the length of discontinuity time. Irradiation in batches was better than one-off irradiation at same dosage in degradation, and the number of irradiation in batches times had little effect on degradation. The length of discontinuity time had a strong impact on it. Under the dose of10kGy and the concentration of1.0mg/L, when discontinuity time reached30min, the degradation rate of endosulfan was about45%and50%. But when it reached120min, that of endosulfan and bifenthrin could be60%and67%.5. Water can accelerate the irradiation degradation of endosulfan and bifenthrin. The results indicated that the irradiated degradation rates of endosulfan and bifenthrin were raised by increasing the moisture content when it was more than1%. When moisture content reached1%, the degradation rate of endosulfan was46.6%, and that of bifenthrin was44.2%; When reached10%, the rates of endosulfan and bifenthrin were51.3%and62.2%.6. Tea polyphenol, caffeine, theanine and vitamin C could influence the irradiation degradation of endosulfan and bifenthrin. The results indicated that the degradation rates of endosulfan and bifenthrin containing tea materials were different with those without them. Tea polyphenol, caffeine, theanine and vitamin C could promote the irradiation degradation of endosulfan, meanwhile they also accelerated irradiation degradation of bifenthrin, but theanine restrained that.