The purpose of the study was to establish an analytical method to simultaneously determine multiple sterols in tobacco leaves rapidly and accurately.In this gas chromatography-triple quadruple tandem mass spectrometry...The purpose of the study was to establish an analytical method to simultaneously determine multiple sterols in tobacco leaves rapidly and accurately.In this gas chromatography-triple quadruple tandem mass spectrometry(GC-MS/MS)based method,various conditions for sterols extraction were assessed and the instrumental operation parameters were optimized with 5α-cholane as an internal standard.Using this method,eight plant sterols,namely lanosterol,campesterol,chenodeoxycholic acid,cholesterol,β-sitosterol,stigmasterol,dihydrotachysterol and ergosterol,were separated in less than 30 min.The linear correlation coefficients were over 0.998 9,the low detection limits were in the range of 0.010 3-0.141 4 μg/g.The recoveries were from 87.30% to 115.60%,with low standard deviations.In conclusion,this method demonstrates good repeatability,accuracy,and high sensitivity,and is best suited for rapid analysis of multiple sterols in tobacco leaves.展开更多
Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the...Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the present study,a novel method for the determination of 14 PASHs in PM_(2.5) was developed using atmospheric pressure gas chro matography-tandem mass spectrometry(APGC-MS/MS).Atmospheric pressure chemical ionization was operated with multiple reaction monitoring in positive ionization mode.High sensitivity(method detection limit <1.673 pg/m^(3)),acceptable re coveries(67.6%-120.8%) and precisions(RSD of 2.2%-15.4%) were obtained.The method was successfully applied for analyzing PASHs in 10 PM_(2.5) samples collected from Taiyuan,a typical industrial city in China,in 2016,The total concentrations were from 929 pg/m^(3) to 14,593 pg/m^(3).The determined levels indicated that further investigations on environmental fate and toxicities of PM_(2.5)-bound PASHs may be needed.展开更多
A new method was developed for the simultaneous analysis of 12 pesticide residues in onion and fennel by gas chromatography(GC)-triple quadrupole mass spectrometry(MS/MS)-electron impact ion source(EI)-select reaction...A new method was developed for the simultaneous analysis of 12 pesticide residues in onion and fennel by gas chromatography(GC)-triple quadrupole mass spectrometry(MS/MS)-electron impact ion source(EI)-select reaction monitoring mode(SRM).The 12 pesticide includes fungicide,acaricide,carbamate and plant growth regulator pesticide.The complicated matrix samples of onion and fennel were extracted by acetonitrile,cleaned up by solid phase extraction of Carb/PSA.By optimizing the GC-MS/MS-SRM parameters,the interference from clean-up procedure was further removed and 12 pesticide residues were determined accurately.The average recoveries for most pesticides(at the spiked level of 0.05-0.20 mg/kg) were between 114%-156%,the relative standard deviation(RSD) of the method was less than 20%,and the limit of detection were 0.5-5 μg/kg.展开更多
文摘The purpose of the study was to establish an analytical method to simultaneously determine multiple sterols in tobacco leaves rapidly and accurately.In this gas chromatography-triple quadruple tandem mass spectrometry(GC-MS/MS)based method,various conditions for sterols extraction were assessed and the instrumental operation parameters were optimized with 5α-cholane as an internal standard.Using this method,eight plant sterols,namely lanosterol,campesterol,chenodeoxycholic acid,cholesterol,β-sitosterol,stigmasterol,dihydrotachysterol and ergosterol,were separated in less than 30 min.The linear correlation coefficients were over 0.998 9,the low detection limits were in the range of 0.010 3-0.141 4 μg/g.The recoveries were from 87.30% to 115.60%,with low standard deviations.In conclusion,this method demonstrates good repeatability,accuracy,and high sensitivity,and is best suited for rapid analysis of multiple sterols in tobacco leaves.
基金financial support from the National Natural Science Foundation of China (Nos.91843301 and 91543202)National Key Research and Development Program Cooperation on Scientific and Technological Innovation in Hong Kong,Macao and Taiwan (No. 2017YFE0191000)。
文摘Research on pollution characteristics and toxicities of emerging polycyclic aromatic sulfur heterocycles(PASHs) in PM_(2.5) has not been reported due to the lack of analytical method with the needed performance.In the present study,a novel method for the determination of 14 PASHs in PM_(2.5) was developed using atmospheric pressure gas chro matography-tandem mass spectrometry(APGC-MS/MS).Atmospheric pressure chemical ionization was operated with multiple reaction monitoring in positive ionization mode.High sensitivity(method detection limit <1.673 pg/m^(3)),acceptable re coveries(67.6%-120.8%) and precisions(RSD of 2.2%-15.4%) were obtained.The method was successfully applied for analyzing PASHs in 10 PM_(2.5) samples collected from Taiyuan,a typical industrial city in China,in 2016,The total concentrations were from 929 pg/m^(3) to 14,593 pg/m^(3).The determined levels indicated that further investigations on environmental fate and toxicities of PM_(2.5)-bound PASHs may be needed.
文摘A new method was developed for the simultaneous analysis of 12 pesticide residues in onion and fennel by gas chromatography(GC)-triple quadrupole mass spectrometry(MS/MS)-electron impact ion source(EI)-select reaction monitoring mode(SRM).The 12 pesticide includes fungicide,acaricide,carbamate and plant growth regulator pesticide.The complicated matrix samples of onion and fennel were extracted by acetonitrile,cleaned up by solid phase extraction of Carb/PSA.By optimizing the GC-MS/MS-SRM parameters,the interference from clean-up procedure was further removed and 12 pesticide residues were determined accurately.The average recoveries for most pesticides(at the spiked level of 0.05-0.20 mg/kg) were between 114%-156%,the relative standard deviation(RSD) of the method was less than 20%,and the limit of detection were 0.5-5 μg/kg.
