Levels,Sources And Risk Assessment Of Exposure To Neonicotinoids In Adolescents In Chongqing Of Southwest China Based On UPLC-MS/MS Method

Objective: Neonicotinoid insecticides(NNs)are currently the most widely used insecticides in the world.However,experimental studies in vivo and vitro have pointed out that NNs exposure has potential adverse health effects on mammals.Based on this,the aims of this study were to: 1)establish a sensitive,accurate and modified solid phase extraction-ultra high performance liquid chromatography tandem mass spectrometry method suitable for detecting ten NNs markers;2)use the established method to quantitatively detect the concentrations of ten NNs markers in the urine of 386 adolescents in Chongqing urban area,and evaluate the sources of exposure to NNs and health risks.Methods: An improved SPE-UPLC-MS/MS method for detecting 10 NNs markers in human urine was established by optimizing sample pretreatment conditions,chromatographic conditions and mass spectrometry conditions.And a complete methodological evaluation was carried out.Then,the established method was used to detect the exposure concentrations of 386 adolescents in Chongqing urban area.After correcting the concentrations with creatinine,the daily intake was calculated.Finally,the hazard index method was used to evaluate the exposure risk assessment.Results: An extraction crystallization procedure was introduced after the elution step,which effectively removed matrix interferences in the urine and improved the sensitivity of the method.The average recoveries of all target analytes were in the range of 89.1-104.8%,and the lowest detection limits were in the range of 0.001 to 0.02 ng/m L.Among the ten examined NNs,the geometric mean concentrations were in the order as follows: acetamiprid(49.43 μg/g creatinine)>clothianidin(5.01 μg/g creatinine)>imidacloprid(3.80 μg/g creatinine)>thiamethoxam(3.24 μg/g creatinine)>thiacloprid(2.25 μg/g creatinine)>nitenpyram(1.79 μg/g creatinine)>dinotefuran(1.76 μg/g creatinine)>sulfoxaflor(1.65 μg/g creatinine)>imidaclothiz(1.28 μg/g creatinine)>flonicamid(1.01 μg/g creatinine).The detection rates of the ten NNs were 79.3-100.0%.The more fruits and fried,roasted and fried puffed foods were consumed,the easier it was to find NNs in the urine of adolescents in Chongqing urban area.Adolescents whose mothers work in the service and business sectors were more likely to find clothianidin in urine,but less likely to find N-desmethyl-acetamiprid and sulfoxaflor.Nevertheless,hazard quotient and hazard index data exhibited a low health risk caused by the individual and cumulative exposure to neonicotinoids on the basis of the reference limit values recommended by the U.S.Environmental Protection Agency and the National Food Safety Standard of China.Conclusion: This work established a sensitive and accurate UPLC-MS/MS method suitable for simultaneously analyzing the exposure concentrations of 10 NNs in human urine.The high detection rates of NNs indicated that adolescents in Chongqing urban area were generally exposed to NNs.Ingestion of fruits and fried,roasted and fried puffed foods were potential sources of exposure to NNs in adolescents in urban area of Chongqing.Adolescents whose parents work in the service and business sectors were more likely to find clothianidin in urine.The results of a cross-sectional study of this work showed that exposure to NNs had a low risk of health effects on adolescents.