A Study On Residue And Dietary Exposure Risk Assessment Of Chlorpyrifos In Edible Tissues Of Duck

With the rapid development of China’s national economy and the improvement of people’s living standard, great changes have taken place in people’s dietary structure. The proportion of animal-derived food such as livestock and poultry products in the daily diet is increasing by years, the quality and safety of this food not only affect consumers’health and safety, but also our economic development, international trade, and social stability, so it is an urgent problem must be resolved to carry out the study of how the poison which stayed in the animal products transforms and risk assessment, as long as the establishment of scientific evaluation standard and system. Pesticides may pose threat to the customers’health by feed for animals, and also has greatly hindered the exportation of agricultural products.We choose chlorpyrifos as a representative pesticide which is our current larger usage pesticide in this test, to study the final residue of chlorpyrifos in the field of fodder crops, the processing factors of chlorpyrifos in feed processing, as well as the residual distribution law in the edible tissues of duck, and dietary exposure risk assessment, respectively, to clarify the fate and potential hazards of chlorpyrifos in the crop-feed-livestock and poultry food chain, to provide a scientificbasis for the risk assessment of pesticide residues in livestock and poultry products. The main findings are as follows:1. An analytical method was described for determining of chlorpyrifos and its metabolites TCP in the crops, feed, edible tissues of duck. The samples were extracted with acetonitrile, and measured by gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS). When you add a level of0.01～0.5mg·kg-1, the recovery range of chlorpyrifos in crops and feed was75.9%to114.6%, RSD was rang from1.6%to12.6%, the recovery range of TCP was71.7%to115.8%, RSD was rang from1.8%to12.1%; the recovery range of chlorpyrifos in edible tissues of duck was between70.3%to114.2%, RSD was rang from1.2%to14.9%, the recovery range of TCP was between68.9%to98.4%, RSD was rang from1.3%to13.2%. In the instrument operating conditions, the minimum detectable concentration of chlorpyrifos and TCP in crops and feed were0.5μg·kg-1and0.2μg·kg-1, the minimum detectable concentration of chlorpyrifos and TCP in edible tissues of duck were0.5μg·kg-1and0.2μg·kg-1. The method satisfied the requirement of chlorpyrifos and its metabolites TCP residue analysis in real samples for the method accuracy, precision, etc.2. The final residue of chlorpyrifos and its metabolite TCP in field fodder crops (corn, soybeans and paddy) was studied.480g/L chlorpyrifos EC was sprayed two or three times at recommended dose and double recommended dose in this final residue tests, respectively, in the last7days and14days after spraying to take rice,10days and20days after taking corn,14and28days to take soybeans, and then after processing system like brown rice, rice bran, corn, soybean samples for testing, chlorpyrifos residues in brown rice and rice bran, followed by corn and soybeans.3. The processing factors of chlorpyrifos was studied in feed processing. Including two aspects:processing of the feed materials (soybean) and pellet feed processing, the feed raw materials soybean cake, after the oil press squeezing obtained by processing of the factor of0.2616; in the process of the feed pellets after the first pulverization processing process, corn, soybean meal, brown rice, rice bran processing factors were0.9559,0.9276,0.8921,0.8782; flat after the second step of grinding grain processing process, corn, soybean meal, brown rice, rice bran processing factors were0.7122,0.7615,0.6322,0.6905.4. The residue of chlorpyrifos in edible tissues of duck was studied.7-day-old duck was fed with containing three gradient chlorpyrifos2.662mg·kg-1,7.986mg·kg-1,26.62mg·kg-1feed, fed42days and killed, meat, liver, kidney, heart, intestines, duck tongue, duck blood, duck gizzards and duck fat tissue, the results showed that chlorpyrifos residue major in fat, followed by the tongue, duck intestines,then there were duck meat, kidney, liver, heart, duck gizzards, duck blood.5. According to the chlorpyrifos and TCP residues in the edible tissues of duck, the chlorpyrifos and its metabolite TCP dietary exposure risk assessment was studied. According to the poultry meat intake of residents of different groups of people in our country and body weight data, point assessment method, different ages, different gender groups, we studied short-term acute dietary exposure assessment and long-term chronic dietary exposure assessment of chlorpyrifos and its the metabolite TCP, the risk of acute dietary exposure value(%ARfD) and chronic dietary risk value (%ADI) From the results, duck meat, duck intestines, duck tongue chlorpyrifos%ADI is less than100, belonging to a lower level of risk.