Study On The Migration And Risk Assessment Of Pesticide Residues During Chinese Liquor Production From Sorghum

Sorghum is the main raw grain during the production of Chinese liquor.However,it is unavoidably to use pesticides due to the occurrence of pests,diseases and weeds in the growth of sorghum.Moreover,the fumigants were also used to minimize the losses from storage pests during the period of storage.These all cause the pesticide residues in sorghum,and then inducing the potential risk to Chinese liquor.Currently,it is lack of the basic data of pesticide residues in cereals,lack of systemic research of the pesticide residue migration and the processing factor(Pf)during the production of Chinese liquor,and lack of the basic data and results of risk assessment.Consequently,it has practical significance to study the multi residue analysis method for the determination of the pesticide residues in liquor-making raw grains and Chinese liquor,and it is of practical and guiding significance to study the the migration and risk assessment of pesticide residues during Chinese liquor production from sorghum.In this study,on the basis of the pesticide registration on liquor-making raw grains,a simple and rapid multi-plug filtration cleanup(m-PFC)method was developed for the determination the 124 pesticide residues in liquor-making raw grains(including sorghum,rice,wheat and maize),Chinese liquor and rice hull.Results showed that the recoveries for the 121 pesticides in all matrices were between 71 and 121%with relative standard deviations(RSDs)below 17%except cyprodinil,diflufenican and prothioconazole,which had lower recoveries.Good linearities were obtained for all pesticides with calibration curve coefficients(R2)larger than 0.9901 in the range of 10~100 μg/L.The limits of detection(LOD)were between 0.03 and 1.5 μg kg-1 and the limits of quantification(LOQ)was between 0.1 and 5.0 μg kg-1 for the pesticides in all matrices.Then the method was applied to detect the pesticide residues in Chinese liquor,sorghum,rice,wheat,maize and rice hull sample which were obtained from Beijing,Guizhou,Sichuan,Shanxi,Jiangsu,Shandong,Shaanxi,Jiangxi,Hubei,Anhui,Henan,Hebei in the year of 2014-2015.Results indicated that the pesticide residues in liquor-making raw grain and rice hull were more serious,while the pesticide residues detected in Chinese liquor were mainly betweenl~10 μg/kg.According to the detection and registration of pesticides in sorghum and the traditional process of Chinese liquor,the migration and processing factor of five grain-storage-used insecticides and eight commonly used pesticides were studied during the production of Chinese liquor through fortified residue in laboratory.Moreover,the migration and processing factor of the other six pesticides were also studied through incurred residue in field experiment.The Pf s for all pesticides after each step were between 0.021 and 0.99 which indicated that the residue level of studied pesticides decreased with the liquor-making process.During the soaking process,the reduction of pesticide residues was related to their vapor pressures,and the removal rate increased with the rise of vapor pressure,which obviously reduced the residues of dichlorvos and phorate by 87%and 91%,respectively.The steaming process involving continuous heating further reduced pesticide residues by 22-83%mainly due to evaporation or thermal degradation.The fermentation reduced pesticide residues by 36%~76%.The residue of deltamrthrin,phorate,procymidone,tebuconazole,bifenthrin,beta-cypermethrin,esfenvalerate,pyraclostrobin and difenoconazole were eliminated after distillation process,which demonstrated that the process was effective for reducing the pesticide residues in Chinese liquor.The Pf s of the overall process for fenitrothion,pirimiphos-methyl,malathion,atrazine,metolachlor,chlorpyrifos and triadimefon were between 0.002 and 0.015,and the transfer rate for these pesticides from liquor-making raw grains to Chinese liquor were in the range of 0.034%~0.39%,which were very low,indicating that the liquor-making process could significantly reduce the pesticide residues in raw grain.Based on the per capita dietary intake of sorghum and Chinese liquor,the dietary risk assessment of the detected pesticides in sorghum and Chinese liquor were conducted.Results showed that the NEDIs of the detected pesticides were lower than their ADIs,and the RQC of the detected pesticides were less than 0.52%,indicating that the detected pesticides in sorghum and Chinese liquor accounted for only a small proportion in the chronic dietary risk.Moreover,the NESTIs of the detected pesticides were Iess than their ARfDs,and the RQa of the detected pesticides were also below 8.4%,which indicated that the acute dietary risk of the detected pesticides in sorghum and Chinese liquor was acceptable.In conclusion,the multi-residue analytical method for the simultaneous determination of 124 pesticide residues in liquor-making raw materials and Chinese liquor was established in this study,which could be used for daily supervision and quality guarantee.The pesticide residues in liquor-making raw materials and Chinese liquor were screened in order to provide the basic data for dietary risk assessment.Then the typical pesticides were selected to study the rule of their migration and processing factor during the production of Chinese liquor,which provided guidance to the liquor enterprise.Finally,the dietary risk assessment of the detected pesticides in sorghum and Chinese liquor were evaluated.