An ultrahigh performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-MS/MS)was established to quickly and accurately determine the content of oleuropein in cosmetics.The samples were extracte...An ultrahigh performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-MS/MS)was established to quickly and accurately determine the content of oleuropein in cosmetics.The samples were extracted with methanol-aqueous solution,and the mobile phase with methanol-formic acid solution(0.1 mol/L)=40∶60 was separated by Agilent ZORBAX Eclipse Plus C18(2.1 mm×50 mm×1.8μm-Micron)column temperature 30℃,flow rate 0.3 mL/min.The MS end was detected by electrospray negative mode ionization(ESI-)and multiple reaction monitoring(MRM)mode.The results show a good linear relationship in the range of 0.002~5 mg/L,with a correlation coefficient R2 of 0.999,5.Method recovery range from 84.2%~107.6%and the relative standard deviation RSD is 5.8%.The detection time is 5 min,the detection limit is 0.000,6 mg/L,and the limit of quantification is 0.002 mg/L.This method has the advantages of convenient operation,low quantification limit,high precision and good repeatability,and is suitable for measuring the content of oleuropein in many kinds of cosmetics.展开更多
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
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
Objective:Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest,Sitophilus oryzae(L.),Rhyzopertha dominica(F.),and Tribolium castaneum(Herbst)were investigated.Materials and M...Objective:Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest,Sitophilus oryzae(L.),Rhyzopertha dominica(F.),and Tribolium castaneum(Herbst)were investigated.Materials and Methods:Hundred grams of C.capitatum powder was sequentially extracted with a series of solvents of increasing polarity in a Soxhlet apparatus and the extracts were concentrated on rotary evaporator to make it solvent free and the residue dissolved in a known volume of methanol and the solution was assayed for insecticidal activity by the fumigant toxicity.Hexane extract which showed maximum activity was selected for the preparation of herbal formulation and for its insecticidal properties and phytotoxicity.The herbal formulation obtained from leaves of C.capitatum was investigated by GCMS and GC/FID.Results:Clerodendrum capitatum ethyl extract had a very strong repellent activity to adults of all three major stored grain insects and was significantly repellent at a 1.58 mg/cm^(2).The hexane extract(oil)had high fumigant activity with LC_(50) values in the range between 25 and 32μg/L.A total of 14 components representing 97.8%of the formulation were identified and the main compounds in the formulation were found to be 2-Heptanone,3-methyl(33.9%)and Hexahydrofarnesyl acetone(25.3%)followed by 3-Dodecen-1-al(10.2%)and 8-Methyl-1-undecene(4.9%).Further,herbal formulation was found to be highly toxic to mixed age cultures of all three major stored grain insect pests which recorded 80%-90%mortality at dose of 200μg/L in 24 h exposure,where as 100%mortality achieved at dose of 200μg/L in 72 h exposure,respectively.Conclusion:The results indicate that extracts and formulation of C.capitatum has the potential to be developed in to a natural insecticide or repellent for controlling of stored product beetles.展开更多
文摘An ultrahigh performance liquid chromatography-triple quadrupole tandem mass spectrometry(UPLC-MS/MS)was established to quickly and accurately determine the content of oleuropein in cosmetics.The samples were extracted with methanol-aqueous solution,and the mobile phase with methanol-formic acid solution(0.1 mol/L)=40∶60 was separated by Agilent ZORBAX Eclipse Plus C18(2.1 mm×50 mm×1.8μm-Micron)column temperature 30℃,flow rate 0.3 mL/min.The MS end was detected by electrospray negative mode ionization(ESI-)and multiple reaction monitoring(MRM)mode.The results show a good linear relationship in the range of 0.002~5 mg/L,with a correlation coefficient R2 of 0.999,5.Method recovery range from 84.2%~107.6%and the relative standard deviation RSD is 5.8%.The detection time is 5 min,the detection limit is 0.000,6 mg/L,and the limit of quantification is 0.002 mg/L.This method has the advantages of convenient operation,low quantification limit,high precision and good repeatability,and is suitable for measuring the content of oleuropein in many kinds of cosmetics.
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.
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.
文摘Objective:Insecticidal activity of Clerodendrum capitatum extracts against the stored product insect pest,Sitophilus oryzae(L.),Rhyzopertha dominica(F.),and Tribolium castaneum(Herbst)were investigated.Materials and Methods:Hundred grams of C.capitatum powder was sequentially extracted with a series of solvents of increasing polarity in a Soxhlet apparatus and the extracts were concentrated on rotary evaporator to make it solvent free and the residue dissolved in a known volume of methanol and the solution was assayed for insecticidal activity by the fumigant toxicity.Hexane extract which showed maximum activity was selected for the preparation of herbal formulation and for its insecticidal properties and phytotoxicity.The herbal formulation obtained from leaves of C.capitatum was investigated by GCMS and GC/FID.Results:Clerodendrum capitatum ethyl extract had a very strong repellent activity to adults of all three major stored grain insects and was significantly repellent at a 1.58 mg/cm^(2).The hexane extract(oil)had high fumigant activity with LC_(50) values in the range between 25 and 32μg/L.A total of 14 components representing 97.8%of the formulation were identified and the main compounds in the formulation were found to be 2-Heptanone,3-methyl(33.9%)and Hexahydrofarnesyl acetone(25.3%)followed by 3-Dodecen-1-al(10.2%)and 8-Methyl-1-undecene(4.9%).Further,herbal formulation was found to be highly toxic to mixed age cultures of all three major stored grain insect pests which recorded 80%-90%mortality at dose of 200μg/L in 24 h exposure,where as 100%mortality achieved at dose of 200μg/L in 72 h exposure,respectively.Conclusion:The results indicate that extracts and formulation of C.capitatum has the potential to be developed in to a natural insecticide or repellent for controlling of stored product beetles.
