Study On Residues Dispersion Of Cypermethrin And Induction Of CAT In Carassius Auratus

Cypermethrin is a important kinds of synthetic pyrethroids, because of powerfull effective and low toxic residues, it was not only used to control insect pests in agriculture and be used in room and public. Althroug it was no harm to human and other animal,It has been suggested that synthetic pyrethroids are readily absorbed by the gills and fish even at very low concentrations.This master paper used Carassius auratus as experiment animal, set up the detect method by applying matrix solid-phase dispersion method (MSPD) as pre-treatment, and GC-ECD as detector. We studied the toxic of cypermethrin in carassius auratus by biochemical technology, caculated the 96h LC50 of cypermethrin to carassius auratus. Studied the accumulation and diserration of cypermethrin in muscle, gill and liver of carassius auratus, changing of CAT activity in muscle,liver and kidney. We give the cypermethrin toxic effect from the whole body of carassius auratus and muleculer level. The main study results are bellow:1,In the research, matrix solid-phase dispersion method was used to extracted and purify cypermethrin from carassius auratus tissues, the main conditions of MSPD were optimized, a pretreatment method with 0.5g neutral aluminum oxide as assistant absorbent,1.5g florisil as abosorbent,20mL 20% ethyl-acetate/petroleum ether as elute and the rate of sample and filling 1:3,4min as the rubbing time Were established. This method has good liner range, coefficient was 0.9993; The limited detection was 1.4-0.lμg/kg.Adding standard materials to blank sample of carassius auratus tissues for the test of recovery, the mean recoveries were found in a range of 84.9%～106.1% with relative standard deviation in the range of 3.4%～6.1%. Proved by actual test samples, this method can meet the pyrethroids in the routine analysis of residues in aquatic products requirements.2,The results of acute toxicity revealed that 96hLC50 of cypermethrin was 1.688μg /L for Carassius auratus, with mean body length 8.7cm and menn body weight 15.5g. The safety Concentration of cypermethrin of the fish was 0.1688μg/L. According to the indexes of biological detect, cypermethrin was a high toxic pesticide for Carassius auratus.3^ The cumulative results of three tissues(gill, muscle and liver) in the low concentration of cypermethrin within 96h group within achieved dynamic equilibrium, and the high concentration group in 96h has no obvious signs of a dynamic equilibrium. The maximum accumulation in high concentration of cypermethrin in the three tissues was significantly higher than that of low concentrations of cypermethrin. From the specific performance of dynamic curve, high and low concentrations of cypermethrin in various tissues has consistent results. At first increased and then decreased, cases in which the enrichment of the liver is more complex, both high and low concentrations have shown 3 fluctuations. The largest concentration was shown in high group in the gill as 11.43μg/kg. The bioconcentration enrichment factor of cypermethrin in various tissues as follows:gills> liver> muscle. Exposure the fish to low concentrations of cypermethrin for the study subjects of cypermethrin release. Results showed that cypermethrin in the gills, muscle, liver, which have achieved dynamic equilibrium quickly decreased after released into the water, the release half-life organizations as follows:gills> muscle> liver.4,Carp in various concentrations of cypermethrin continuous exposure 120h, in addition to low concentrations of cypermethrin on muscle CAT activity compared with the control group did not differ (P>0.05), the low concentrations of cypermethrin in the liver and the concentration of CAT activity and high concentration group Group of continuous exposure to cypermethrin on muscle and liver CAT activity in the early exposure compared with the control group were significantly different (P<0.01). Exposed to the same period, the higher the concentration on the inhibition of the organizations became more significant. High concentration group at any time the inhibitory effect on the liver and other tissues were significantly different than (P<0.01). Continuous exposure to cypermethrin in the 120h, the organizations in the changes of CAT activity was decreased and then increased, and CAT activity in the liver is greater than the muscle and kidney CAT activity changes.