Studies On Environmental Behavior Of Alkaloids From Tripterygiun Wilfordii Hook.F.

Alkaloids are the main insecticidal substances of Tripterygium wilfordii Hook.f. and have very good insecticidal activity to many kinds of pests, such as Plutella xylostella , Mythimna separate and so on. To provide a powerful and scientific basis for registration, popularization and application of alkaloids from Tripterygium wilfordiiHook.f.,and this study focused on the environmental behavior of alkaloids from Tripterygium wilfordii Hook.f., according to'Experimental Guildeline for Environmental Safety Evaluation of Chemical Pesticide'. The main results and conclutions are as follows:(1). The mothed for determination of alkaloids residues in tapes water, soil by UV at 268nm was established. The mothed has good reproducibility and accuracy . Alkaloids recoveries determined in tape water and soil by UV at 268 nm were both more than 75 %.(2). The results of soil leaching test showed that : Alkaloids were strongly adsorbed by soils from Noetheast, Henan, and guanzhong. The adsorption rate were 98.30 %,97.25 %,98.83% in the 0-10 cm soil paragraph, so the alkaloids are hardly leach, and safe to groundwater.(3). Adorption of soils to alkaloids from Tripterygium wilfordii Hook.f.was tested. The adorption of alkaloids in three soil samples, Northeast soil, Guanzhong soil, Henan soil, were fitted to Freundlich. And the Kd were 15.21, 11.05 and 8.62, belong to IV, hardly adorption. The adorption isotherm was L-type. So low concentration of alkaloids was strongly adorpted by soil; and high concentration of Tripterygium wilfordii alkaloids may pollute the environment.(4). The degradation of alkaloids from Tripterygium wilfordii Hook.f. were studied. Results showed that: The degradation of alkaloids in three sterilized soils: in Peach soil, crop soil, vegetable soil, were fasted, and the half-life were 10.060 d,9.916 d,8.887 d , less than one month. So the alkaloids are easily degradatable in soil.(5) We studied the degradation of alkaloids from Tripterygium wilfordii Hook.f. in different water. Alkaloids was stable in pH 7.0 buffer water; the half-life of 50℃was 5.180 d, the half-life of 25℃was 14.204 d in pH 9.0 buffer water; The biological half-life of alkaloids from Tripterygium wilfordii Hook.f. in Weihe water were 5.645 d under 50 ℃,20.033 d under 25℃; The biological half-life of alkaloids in pond water were 5.188 d under 50℃, 12.649 d under 25℃. The studies showed that, Alkaloids from Tripterygium wilfordii Hook.f. degrade fastly in pH 9.0 water, river and fish ponds.To sum up, alkaloids from Tripterygium wilfordii Hook.f. are more secure . There will be no serious impact on the environment after use.