[Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified ...[Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified with anhydrous magnesium sulfate,sodium chloride and primary secondary amine(PSA)powder,and then loaded on the machine.The full information spectrum was collected by positive ion mode and screened by comparing with the spectrum library,and 20 kinds of pesticide residues were quantitatively analyzed.[Results]The detection limits of 20 pesticide residues were 0.0002-0.0100 mg/kg,and they showed good linearity in the range of 0.0005-0.1000μg/mL(R 2≥0.995).The recoveries ranged from 62.8%to 106.3%.[Conclusions]This method is rapid,simple,sensitive and non-targeted,and can be used for rapid screening of multiple pesticide residues in strawberry.展开更多
In the past 12 years several studies have screened lists of thousands of chemicals available in the industrial chemical inventories of the European Union,the USA and Canada with the goal of identifying and prioritizin...In the past 12 years several studies have screened lists of thousands of chemicals available in the industrial chemical inventories of the European Union,the USA and Canada with the goal of identifying and prioritizing chemicals which are persistent(P),bioaccumulative(B)and toxic(T).Most studies have selected chemicals based on whether their predicted P and B properties and their long-range transport potential exceed guideline thresholds for evaluation of persistent organic pollutants(POPs).A major goal of this study was to review this recent literature on computer-based or‘in silico’screening for POPs.A second goal was to review other approaches for finding previously unidentified chemicals of concern including targeted and non-target analytical approaches that might use lists of suspect chemicals developed from‘in silico’screening studies.Eight studies were reviewed along with several others which examined the screening process and its uncertainties.From these studies we assembled a list of 3421 chemicals,after removing duplicates and substances already on the Stockholm Convention on POPs.About 52%of these were halogenated,while 48%consisted of a broad range of non-halogenated organics.This list was then further analysed by calculating an overall“POPs score”for transport and accumulation in the Arctic for each substance using predicted partition coefficients,overall persistence,transfer efficiency,and bioaccumulation factor.A shorter list of twenty-five substances was developed based on their POPs score ranking.These substances had not been previously analysed in environmental media but were nevertheless on current or recent chemical inventories indicating significant commercial use.展开更多
The proliferation of adulterated health foods and beverages in the market demands a comprehensive analytical strategy to identify the adulterants,particularly those of isomeric phosphodiesterase 5(PDE5)inhibitors.An i...The proliferation of adulterated health foods and beverages in the market demands a comprehensive analytical strategy to identify the adulterants,particularly those of isomeric phosphodiesterase 5(PDE5)inhibitors.An instant coffee premix(ICP)purchased from an online retailer was flagged for suspected adulteration through PDE5 inhibition assay.The ICP was then analysed using suspected-target and non-targeted screenings of a liquid chromatography-quadrupole time-of-flight mass spectrometry.Based on these findings,a PDE5 inhibitor initially assigned as compound X was isolated from the ICP by employing a liquid chromatography-diode array detection before its structural elucidation with liquid chromatography-ultraviolet(LC-UV)spectroscopy and nuclear magnetic resonance(NMR)spectroscopy.The suspected-target screening matched the protonated molecule([MþH]þ)precursor ion of compound X at m/z 499.2310 with two suspected analytes that are structural isomers of one another.The fragmentation patterns of compound X were comparable to those analogues in the dithiocarbodenafil group through the non-targeted screening.These findings,complemented by the LC-UV and NMR spectroscopy data,together with the chromatographic separation of related structural isomers,conclude the identity of compound X.To our best knowledge,this is the first study to report the presence of 3,5-dimethylpiperazinyl-dithiodesmethylcarbodenafil in an ICP sample.展开更多
基金Supported by Scientific Research Project of General Administration of Customs (2021DK16).
文摘[Objectives]The paper was to establish a rapid screening method of pesticide residues in strawberry based on HPLC-QTOF/MS SWATH acquisition mode.[Methods]The strawberry sample was extracted with acetonitrile,purified with anhydrous magnesium sulfate,sodium chloride and primary secondary amine(PSA)powder,and then loaded on the machine.The full information spectrum was collected by positive ion mode and screened by comparing with the spectrum library,and 20 kinds of pesticide residues were quantitatively analyzed.[Results]The detection limits of 20 pesticide residues were 0.0002-0.0100 mg/kg,and they showed good linearity in the range of 0.0005-0.1000μg/mL(R 2≥0.995).The recoveries ranged from 62.8%to 106.3%.[Conclusions]This method is rapid,simple,sensitive and non-targeted,and can be used for rapid screening of multiple pesticide residues in strawberry.
基金We thank Eva Kruemmel for helpful review and comments on behalf of the Inuit Circumpolar Council,on the earlier version of this article which appeared as Chapter 4 of the AMAP Chemicals of Emerging Arctic Concern assessment report.KV received funding from the Danish Environmental Protection Agency under the Danish Cooperation for Environment in the Arctic(DANCEA)(grants no.MST-112-191 and MST-113-00082).DCGM was supported by the King Carl XVI Gustaf Professorship in Environmental Science at the Dept.Of Environmental Science and Analytical Chemistry,Stockholm University during 2018-19。
文摘In the past 12 years several studies have screened lists of thousands of chemicals available in the industrial chemical inventories of the European Union,the USA and Canada with the goal of identifying and prioritizing chemicals which are persistent(P),bioaccumulative(B)and toxic(T).Most studies have selected chemicals based on whether their predicted P and B properties and their long-range transport potential exceed guideline thresholds for evaluation of persistent organic pollutants(POPs).A major goal of this study was to review this recent literature on computer-based or‘in silico’screening for POPs.A second goal was to review other approaches for finding previously unidentified chemicals of concern including targeted and non-target analytical approaches that might use lists of suspect chemicals developed from‘in silico’screening studies.Eight studies were reviewed along with several others which examined the screening process and its uncertainties.From these studies we assembled a list of 3421 chemicals,after removing duplicates and substances already on the Stockholm Convention on POPs.About 52%of these were halogenated,while 48%consisted of a broad range of non-halogenated organics.This list was then further analysed by calculating an overall“POPs score”for transport and accumulation in the Arctic for each substance using predicted partition coefficients,overall persistence,transfer efficiency,and bioaccumulation factor.A shorter list of twenty-five substances was developed based on their POPs score ranking.These substances had not been previously analysed in environmental media but were nevertheless on current or recent chemical inventories indicating significant commercial use.
文摘The proliferation of adulterated health foods and beverages in the market demands a comprehensive analytical strategy to identify the adulterants,particularly those of isomeric phosphodiesterase 5(PDE5)inhibitors.An instant coffee premix(ICP)purchased from an online retailer was flagged for suspected adulteration through PDE5 inhibition assay.The ICP was then analysed using suspected-target and non-targeted screenings of a liquid chromatography-quadrupole time-of-flight mass spectrometry.Based on these findings,a PDE5 inhibitor initially assigned as compound X was isolated from the ICP by employing a liquid chromatography-diode array detection before its structural elucidation with liquid chromatography-ultraviolet(LC-UV)spectroscopy and nuclear magnetic resonance(NMR)spectroscopy.The suspected-target screening matched the protonated molecule([MþH]þ)precursor ion of compound X at m/z 499.2310 with two suspected analytes that are structural isomers of one another.The fragmentation patterns of compound X were comparable to those analogues in the dithiocarbodenafil group through the non-targeted screening.These findings,complemented by the LC-UV and NMR spectroscopy data,together with the chromatographic separation of related structural isomers,conclude the identity of compound X.To our best knowledge,this is the first study to report the presence of 3,5-dimethylpiperazinyl-dithiodesmethylcarbodenafil in an ICP sample.
