The Elimination Effect Of Chlorpyrifos By Processing And Dietary Exposure Assessment In Cowpea

Study on the removal of the chlorpyrifos in cowpea with different cleaning methods, processing methods, the change of processing factors and Vc contents before and after processing was carried out with laboratory simulation test. Cowpea chlorpyrifos residue detection data was combined2002national dietary survey data of different ages and genders dietary survey data with laboratory simulation soak. The importance of process factors were determined and assessed by different processing ways with dietary exposure risk comparisons, before and after processing laboratory simulation soak. Cowpea chlorpyrifos exposure levels and exposure risk differences varied significantly. The main results were as follows:The chlorpyrifos residues on cowpea were determined after comparing different processing methods by using gas chromatography. It included immersing in water, washing after immersion,1%NaHCO3immersing,1%Na2CO3immersing, vinegar immersing, dishwashing liquid and salt solution on cowpea. The results showed that waterlogging was best method to remove chlorpyrifos. The removal rate range of residues was between33.33-70.71%and the processing factor range was between0.2928-0.6638after waterlogging. The removal rate of residues ranged within45.62%-69.92%and processing factors,0.3008-0.5438by flushing after different waterlogging with different times. The removal rate of flushing after different1%Na2CO3waterlogging with different times was ranged from23.33%to41.56%, while the processing factor,0.5844-0.7667. The removal rate range by flushing after1%NaHCO3waterlogging was25.56%-49.29%, while the processing factor range was0.5113-0.7474. The removal rate range of residues was26.64%-33.87%and processing factor range was0.6613-0.7336by flushing after different vinegar waterlogging at different times. The removal rate range of residues was17.58%-41.89%and processing factor range was0.5811-0.8242by flushing after different washing agent waterlogging at different times. The removal rate range of residues was between8.10%-13.47%and processing factor range was between0.8653-0.9290by flushing after different washing agent waterlogging at different times.The best way to remove of chlorpyrifos was washing after soaked in the water seven cleaning ways and the optimum cleaning condition was:washing2mins after immersing15mins.The optimum cleaning conditions were picked out,then the cooking processing experiment were carried out.the effects of frying cooking, microwave cooking, blanching, salted cooking, dry processing were studied on the cowpea.The results showed:The removal rate of frying cooking was45.02%-46.53%, and processing factor range was between0.5365-0.5735. The removal rate range by microwave was between15.60%-52.01%, while the processing factor range was between0.4799-0.8440. The removal rate range by cooking was between18.28%-41.92%, and the processing factor range was between0.5919-0.8172. The removal rate range of salted cowpea was between26.47%-32.60%, and the processing factor range was between0.6740-0.7353. The removal rate range by dry cowpea was between21.10%-39.67%, and the processing factor range was between0.6093-0.7890. The best way was to add water during fryingBy laboratory simulation cowpea in various cleaningmethods, the levels of vitamin C was determined. Comparison with different cleaning methods, the content loss of Vc was:1%vinegar solution soaking>1%salt solution soaking>l%Na2CO3solution soaking>l%NaHCO3solution soaking>l%detergent solution soaking> water soaking>washing after water soaking.With different age paragraph groups and different gender of urban inhabitants, of dietary exposure experiments of chlorpyrifos in cowpea to different genders were assessed, with consideration of effects of different processing methods. Acute dietary exposure levels (EXPa), chronic dietary exposure levels (EXPc), acute risk value (%ARfD) and chronic value at risk (%CRfD) were determined.The results showed that:The%ARFD and%CRfD of2-3year. the4-6years, the7-10years was higher than other age groups without considering processing factors,the laboratory simulation for chlorpyrifos cowpea, The%CRfD>100,and it was the high risk group. The%ARfD and%CRfD of other groups were close to the risk level by. The%ARfD and%CRfD of female was higher than male by comparing the dietary exposure assessment results between male and female.By processed Laboratory simulation of chlorpyrifos soaking cowpea which introduced processing factor by being fried, microwave cooking, boiled, salted, dried processing on the cowpea, Real life intake of different age groups and different gender groups of residents decreased to acceptable level. It is in a safe state%ARfD at different age groups and%CRfD which did not introduced the processing factor decreased tol/5.%ARfD under age of18and%CRfD is a little higher than that of other groups.and age of2-3is the most sensitive.Comparing the total dietary assessment,%ARfD of female and%CRfD is higher than that of male.Comparing different processing methods,the dietary intake risk was as follows:salted> dried> boiled> fried> microwave cooking.Assessed laboratory simulation of chlorpyrifos in cowpea soak which introduced processing factor and not introduced, Dietary exposure assessment results which introduced the processing and not introduced,Dietary expousure assessment results which introduced the processing factor more complied with real life intake at different age groups and different gender groups of residents.