| This thesis is on the safety level determination of trichlorfon in breeding waters and related monitoring methods were determinned. In addition, Monitoring methods by gas chromatograph of trichlorfon in breeding waters and testing standard of trichlorfon residue in breeding waters were established based on a great of laboratory investigations.In the experiment of determination of safety level of trichlorfon in breeding waters, the common carp and the crucian carp, which had strong tolerance ability to trichlorfon, were used. The acute toxicity of trichlorfon on crucian carp was carried out. The Turabell Formula: 0.1×96hLC50 was use to determined the top limit of toxic and harmful substances in waters.Toxicity test of trichlorfon on crucian of 96 hour was conducted. the result showed that: LC50 is 63.97mg/L, 95% confidence limit is 63.97mg/L, 95% confidence interval is 57.81~72.11 mg/L. The exposure concentration is respectively is 1/2,1/4,1/8 and 1/16LC50, sample was analysis at 24,48,72and 96 hour after begin of test. The result showed that the activities of cholinesterase in plasma of crucian of test group all were higher than control group; but difference among test group was not found. The trichlorfon influnced the activities of GST in liver of crucian, the activities were first raised and then decreased. The activitiy of CAT in liver of crucian of 1/2LC50 is higher than control group at 96hour after test. The micronuclear rates of crucian almost did not changed, but the dyskaryosis of test group was higher than control group. The common carp and crucian carp were put in the water in the concentration of 0.2, 0.3, 0.4, 0.5, 1.0mg/L of trichlorfon respectively. After 5, 10, 15, 20, 30, 40 and 60days, the concentration of the trichlorfon in the meat were detected with high performance gas chromatography. The result showed that trichlorfon the linear range was 0.02～5.00μg/mL, and the determination limit was 0.02mg/kg, the recover rate and the degree of precision were consistent with the detection requirement. The result also indicated that the residual level of trichlorfon in the fish body conformed to the sanitary standard and the fish meat was safely edible.In the experiment of determination of monitoring methods of trichlorfon in breeding waters, monitoring methods by gas chromatograph was established based on Selection Optimizations including the following parameters: collection and preservation of samples (trichlorfon was easily transtomed), extraction and purification methods, Chromatographic conditions (mainly on the parameters of injection port temperature and detector type), and the methods to determine the background values of trichlorfon (dimethyl phosphite) in the waters and animal bodies. The gas chromatography methods: The column was DB-225 capillary column (30 m×0.25μm×0.32mm), with an oven temperature of 70℃(1min)→180℃(10℃/min,2min)→23℃(30℃/min, 2min), injection port temperature was at 280℃, detector temperature was at 250℃, nitrogen with high purity of >99.999% was used as carrier gas with flow rate of 1.8ml/min, the purity of hydrogen was 99.9%, 1μl samples were injected to GC splitlessly. Accoding to the results of two labs confomatory tests, the standand method of monitoring trichlorfon residue in beeeding waters was estalsihed: the samples are spiked at 0.004~0.250mg/L, the average recovery efficiency of the method was≥75%, The minimum detectable concentration 0.004 mg/L, the variation coefficient≤10%, the linear range was at 0.4~25.0μg/mL.
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