| This experiment was based on Hexaconazole,Spirodiclofen,Difenoconazole,and Fenpropathrin,Lambda-cyhalothrin,Beta-cypermethrin,Fenvalerate,Deltamethrin five pyrethriods pesticide,and the establishment of a multi-residue analysis of pesticides in apples tested in simulated gastric and intestinal fluids,Factors influencing the effectiveness of pesticide residues in apples tested using in vitro gastrointestinal simulation of biological,including simulated gastric and intestinal fluid digestion time,solid-liquid ratio,p H value and so on,and based on the results of the biological effectiveness of the discussed Apple the test for pesticide residues in food security.The main results are as follows:1.Multi-residue analysis of typical pesticides in simulated gastrointestinal fluids of the apple.Hexaconazole,Spirodiclofen,Difenoconazole,and other five pyrethriods pesticides in simulated gastrointestinal fluids are using acetonitrile as solvent extraction.Ultrasonic extraction 30 min,purified by florisil SPE column,eluent acetonitrile of hexaconazole,spirodiclofen,difenoconazole was 20 ml,pyrethroid was20 ml eluting mixture of petroleum ether: ethyl acetate(95: 5,V/V),rinsed twice average,then using GC-ECD for detection.Add recovery experiment results show that: in the 0.1~1.0 mg/kg of the added concentration range,Hexaconazole,Spirodiclofen,Difenoconazole in simulated intestinal fluid.The average recoveries were as follows: 74.55%~107.32%,72.45%~76.48% and 74.89%~105.55%;the relative standard deviation(RSD)were as follows: 2.03%-4.94% 0.68% 3.42%0.69%-3.91%.In simulated gastric fluid.The average recoveries were: 108.61% ~115.35%,84.54% ~ 104.37% and 105.80% ~ 115.55%;the relative standard deviation(RSD)were as follows: 1.46%-2.94% 2.29% 5.12% and 1.89%-4.35%.In the concentration within 0.01 ~ 1.0 mg/kg range,Fenpropathrin,Lambda-cyhalothrin,Beta-cypermethrin,Fenvalerate,Deltamethyrin in simulated intestinal fluid,the average recoveries were: 81.98% ~ 104.55%,73.00% ~ 107.85%,83.21% ~ 107.69%,72.70% ~ 112.79% and 81.46% ~ 98.90%;relative standard deviation(RSD)were as follows: 2.18% to 6.44% 3.24%-6.54% 3.98%-7.72%,3.62%-6.91% and 3.63% ~7.25%.The average recoveries in simulated gastric fluid are as follows: 83.15% ~102.97%,80.36% ~ 102.66%,95.05% ~ 105.01%,88.73% and 87.31% ~ 106.96% ~100.10%;the relative standard deviation(RSD),respectively: 2.32% 4.32% 2.46%4.11% 1.53% 6.21% 2.11% 4.10% 1.28%-5.10%.Method of precision,accuracy,sensitivity analysis are meet the requirements of pesticide residues.2.Different factors which affecting the validity of simulated gastric fluid typical of biological pesticides in apples.In this paper,the solid-liquid ratio,different factors digestion time,p H value on the Apple typical biological pesticides in simulated gastric fluid effectiveness.The results show that: Apple in the test pesticide in simulated gastric reaction stage,when the solid-liquid ratio of 0.05 hexaconazole,bioavailability spirodiclofen,benzene ring yl ether and 5 kinds of pyrethroid pesticides were 57.27 %,79.94%,93.49%,31.22%,28.46%,24.15%,27.64% and 21.68%,and by fitting the data found that the best fit logarithmic correlation coefficients R2 were 0.90 or more,so in simulation stomach reaction stage apples tested pesticides.Bioavailability and solid-liquid ratio logarithmic relationship;and the increase of reaction time,changes in bioavailability in gastric juice is not,Hexaconazole,Spirodiclofen,Difenoconazole and Bioavailability of five kinds of pyrethroids were: 72.99%,27.44%,57.36%,20.06%,29.54%,19.03%,22.02%,24.01%.In gastric fluid,p H value will affect the biological effectiveness of different pesticides,to experiments: Hexaconazole,Spirodiclofen,Difenoconazoler at a p H of 2.12 when its bioavailability maximum respectively:80.00%,28.06%,64.06%.Five kinds of pyrethroid at a p H of 1.91 when its bioavailability has reached the maximum were 7.43%,8.84%,9.73%,11.46%,9.95%,showed a parabolic trend.3.Different factors influence the effectiveness of simulated intestinal fluid typical of biological pesticides in applesIn simulated intestinal reaction stage,the paper discusses the p H value,the digestion time,the ratio and other pesticides in apple typical simulated intestinal fluid biological effectiveness.The results showed that: Difenoconazole has the highest bioavailability,and consistent with Hexaconazole trend,a mean of 7.01 while the highest value in p H,respectively,56.34%,60.86%,while the biological effectiveness of Spirodiclofen p H value reached the highest 26.16% when 6.59.Five kinds of permethrin in Fenpropathrin bioavailability is higher than the other four permethrin,Beta-cypermethrin at a p H of 7.26,the Lambda-cyhalothrin,Fenvalerate,Deltamethyrin Bioavailability have reached the maximum,respectively: 16.39 %,14.73%,18.63%.Five kinds of different influences digestion time pyrethroids Bioavailability performance is not obvious,but has some influence on Hexaconazole,Spirodiclofen,Difenoconazole bioavailability,3.5h when three means biopesticides maximum effectiveness were 88.45%,68.75%,113.43%.When the solid-liquid ratio of 0.05 hexaconazole,bioavailability spirodiclofen,benzene ring yl ether and 5 kinds of pyrethroid pesticides were 63.76%,70.17%,103.52%,35.63%,34.53%,28.95 %,31.58% and 25.90%,by fitting the data found in the solid-liquid ratio of between 0.05 to 0.75,the apples tested Bioavailability and solid-liquid ratio showed a relationship between pesticides and R2 numbers are above 0.93.4.Apple pesticide safety evaluation of the test in the consumption processThat biologically effective concentration of contaminants in samples of biological effectiveness of the product,calculated W(biologically effective concentration,ng/g)= w(the compound content in the sample,ng/g)× bioavailability.In this experiment,the solid-liquid ratio of 0.1g/ml,simulated gastric fluid digestion2h,4h under simulated intestinal digestion conditions calculated Hexaconazole,Spirodiclofen,Difenoconazole,Fenpropathrin,Lambda-cyhalothrin,Beta-cypermethrin,Fenvalerate,Deltamethyrin creature can give concentrations of 0.0704 mg/kg,0.0828mg/kg,0.1465 mg/kg,0.3654 mg/kg,0.0106 mg/kg,0.0665 mg/kg,0.0100 mg/kg,0.0025 mg/kg.ADI value comparison test pesticides,cyhalothrin and cypermethrin were 20?g / kg · d,which is similar to chronic toxicity,and to the maximum residue limits of pesticides in apples Two intake concentration calculated as,biologically effective concentration cyhalothrin is 0.0106 mg/kg,far lower than cypermethrin of0.0665 mg/kg,which is only 1/6,and therefore these two apples pesticide residues on the human body and health risks words,cyhalothrin safer than cypermethrin.Similarly,spirodiclofen,benzene ring yl ether,deltamethrin ADI values are 10 ?g/Kg.d,biologically effective concentration of deltamethrin was 0.0025mg/kg well below the lowest benzene ring yl ether,spirodiclofen,only difenoconazole azole1/59,,therefore apples three pesticides on human health risks in terms of deltamethrin than spirodiclofen,benzene ring yl ether more Safety... |
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