The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a co...The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a cough and asthma relieving agent.Herein,a dimension-enhanced integral approach,by combining ultra-high performance liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(UHPLC/IMQTOF-MS)and intelligent peak annotation,was developed to rapidly characterize the multicomponents from SDS.Good chromatographic separation was achieved within 38 min on a UPLC CSH C18(2.1×100 mm,1.7μm)column which was eluted by 0.1%formic acid in water(water phase)and acetonitrile(organic phase).Collision-induced dissociation-MS^(2)data were acquired by the data-independent high-definition MS^(E)(HDMS^(E))in both the negative and positive electrospray ionization modes.A major components knockout strategy was applied to improve the characterization of those minor ingredients by enhancing the injection volume.Moreover,a self-built chemistry library was established,which could be matched by the UNIFI software enabling automatic peak annotation of the obtained HDMS^(E)data.As a result of applying the intelligent peak annotation workflows and further confirmation process,a total of 53 compounds were identified or tentatively characterized from the SDS,including 29 flavonoids,one uridine derivative,four glucosides,one lignin,one phenolic compound,and 17 others.Notably,four-dimensional information related to the structure(e.g.,retention time,collision cross section,MS^(1)and MS^(2)data)was obtained for each component by the developed integral approach,and the results would greatly benefit the quality control of SDS.展开更多
Milk and dairy products are more and more popular with consumers due to their various nutrients, and their quality and safety issues have always been concerned. Therefore, the development of rapid, accurate and simple...Milk and dairy products are more and more popular with consumers due to their various nutrients, and their quality and safety issues have always been concerned. Therefore, the development of rapid, accurate and simple screening techniques is of great significance. Liquid chromatography-high resolution time-of-flight mass spectrometry has high-resolution and high-throughput detection functions, and has gradually begun to be applied in the detection of milk and dairy products. This paper summarized the application of milk and dairy products in liquid chromatography-high resolution time-of-flight mass spectrometry, laying a foundation for the development of new methods.展开更多
A An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, ...A An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.展开更多
An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, ...An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%-111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.展开更多
The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry ( HR-ICP-MS ) was investigated. To overcome some poteutially problematic spectral iuter...The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry ( HR-ICP-MS ) was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.展开更多
The contents of Mg,Al,Si,Ti,Cr,Mn,Fe,Co,Cu,Ga,As,Se,Cd,Sb,Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).The sample was dissolved in HNO3 and...The contents of Mg,Al,Si,Ti,Cr,Mn,Fe,Co,Cu,Ga,As,Se,Cd,Sb,Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).The sample was dissolved in HNO3 and HCl by microwave digestion.Most of the spectral interferences could be avoided by measuring in the high resolution mode.The matrix effects because of the presence of excess HCl and nickel were evaluated.Correction for matrix effects was made using Sc,Rh and Tl as internal standards.The optimum conditions for the determination were tested and discussed.The detection limits range from 0.012 to 1.76 μg/g depending on the type of elements.The applicability of the proposed method is also validated by the analysis of high purity nickel reference material(NIST SRM 671).The relative standard deviation(RSD) is less than 3.3%.Results for determination of trace elements in high purity nickel were presented.展开更多
Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Sample were decomposed by aqua regia. To overcome some potentially problematic spectra/...Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Sample were decomposed by aqua regia. To overcome some potentially problematic spectra/ interference, measurements were acquired in both medium and high resolution modes. The matrix effects due to the presence of excessive HCl and Au were evaluated. The optimum conditions for the determination was tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits range from 0.01ug/g to 0.28ug/g depending on the elements. The method is accurate, quick and convenient. It has been applied to the determination of trace elements in high purity gold with satisfactory results.展开更多
Identification of novel specialized metabolites or bioactive compounds represents the main objective in the research field of natural product leads and drug discovery. Mass spectrometry (MS) provides a central tool to...Identification of novel specialized metabolites or bioactive compounds represents the main objective in the research field of natural product leads and drug discovery. Mass spectrometry (MS) provides a central tool to expedite and make more efficient the discovery and isolation phases, while minimizing the waste of resources on rediscovery of known compounds. MS contributes acutely to elucidation and identification of numerous species because it allows molecular mass and structural features determination. In particular, identification of the elemental composition of a precursor ion of interest by accurate mass measurement and investigation of dissociative processes undergone by the molecule, represent a worthy methodology to access the structure assignment. The aim of this study was to discover and identify novel antibacterial drugs from microbial source in a jungle of already known compounds. The focus of this paper is on the analytical strategy that permitted the disclosure of a new compound, otherwise confused with other substances. Emphasis is placed on the interpretation of the ESI-MS/MS fragmentation pattern that combined with high resolution mass determination, allowed step by step to properly deduce the exact molecular formula of an unknown component with a molecular weight higher than 1500 Daltons.展开更多
This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile sampl...This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile samples in methanol, the solutions were analyzed by ultra-high performance liquid chromotagraphy/orbitrap high resolution mass spectrometry (UPLC/Orbitrap HRMS). It showed that a good chromatographic separation for these target compounds was achieved by a Hypersil GOLD column (100 mm × 2.1 mm × 1.9 μm) with a gradient elution of methanol and 0.1% aqueous formic acid solution (containing 0.5 mmol/L ammonium acetate). Triclosan and 4-chloro-3,5-dimethyl phenol (PCMX) were detected by the orbitrap HRMS in an electrospray ionization (ESI) negative mode while the other twelve target compounds were detected by orbitrap HRMS in ESI positive mode. Full scan experiment was performed over the range from m/z 100 to m/z 500. These target compounds were routinely detected with mass accuracy below 2 × 10-6 (2 ppm) at the optimized conditions. The results showed that the limits of detection (LODs) were in the range from 0.1 to 0.3 μg/kg. The blank samples were spiked at three levels and their average recoveries varied from 80.5% to 96.3% while the relative standard deviation (RSD) changed from 3.2% to 9.9%. The present method was also applied for the determination of those ultraviolet absorbers and antibacterial agents in the commercial textiles.展开更多
Liquid chromatography coupled to high resolution mass spectrometry(LC-HRMS)was used to establish a high throughput and sensitive method for 18 phthalic acid esters(PAEs)in textiles.The method was applied to screen PAE...Liquid chromatography coupled to high resolution mass spectrometry(LC-HRMS)was used to establish a high throughput and sensitive method for 18 phthalic acid esters(PAEs)in textiles.The method was applied to screen PAEs in 413 textile samples and 7 434 pieces of test data were analyzed.Further discussion was conducted about specific compounds,textile materials,detected value distribution and positive rate of samples.Twenty-nine percent of samples were detected with PAEs,and no samples were detected beyond regulations.Diisobutyl phthalate(DiBP),Dibutyl phthalate(DBP)and Di-2-ethylhexyl phthalate(DEHP)were detected with high frequency,and most samples were fabrics with coating and printing.This study can be used to reflect distribution of phthalate residues in textiles on the market and provide data support for risk assessment of PAEs for textile producers and consumers.展开更多
Pulmonary fibrosis(PF)is an irreversible lung disease that is characterized by excessive scar tissue with a poor median survival rate of 2-3 years.The inhibition of transforming growth factor-β receptor type-I(TGF-β...Pulmonary fibrosis(PF)is an irreversible lung disease that is characterized by excessive scar tissue with a poor median survival rate of 2-3 years.The inhibition of transforming growth factor-β receptor type-I(TGF-β RI)by an appropriate drug may provide a promising strategy for the treatment of this disease.Polygonum cuspidatum(PC)is a well-known traditional Chinese herbal medicine which has an anti-PF effect.Accordingly,a combination of high resolution mass spectrometry with an in silico strategy was developed as a new method to search for potential chemical ingredients of PC that target the TGF-β RI.Based on this strategy,a total of 24 ingredients were identified.Then,absorption,distribution,metabolism,and excretion(ADME)-related properties were subsequently predicted to exclude compounds with potentially undesirable pharmacokinetics behaviour.Molecular docking studies on TGF-β RI were adopted to discover new PF inhibitors.Eventually,a compound that exists in PC known as resveratrol was proven to have excellent biological activity on TGF-β RI,with an IC_(50) of 2.211 μM in vitro.Furthermore,the complex formed through molecular docking was tested via molecular dynamics simulations,which revealed that resveratrol had strong interactions with residues of TGF-β RI.This study revealed that resveratrol has significant potential as a treatment for PF due to its ability to target TGF-β RI.In addition,this research demonstrated the exploration of natural products with excellent biological activities toward specific targets via high resolution mass spectrometry in combination with in silico technology is a promising strategy for the discovery of novel drugs.展开更多
Compared to their linear counterparts,cyclic peptides show better biological activities,such as antibacterial,immunosuppressive,and anti-tumor activities,and pharmaceutical properties due to their conformational rigid...Compared to their linear counterparts,cyclic peptides show better biological activities,such as antibacterial,immunosuppressive,and anti-tumor activities,and pharmaceutical properties due to their conformational rigidity.However,cyclic peptides could form numerous putative metabolites from potential hydrolytic cleavages and their fragments are very difficult to interpret.These characteristics pose a great challenge when analyzing metabolites of cyclic peptides by mass spectrometry.This study was to assess and apply a software-aided analytical workflow for the detection and structural characterization of cyclic peptide metabolites.Insulin and atrial natriuretic peptide(ANP)as model cyclic peptides were incubated with trypsin/chymotrypsin and/or rat liver S9,followed by data acquisition using TripleTOF?5600.Resultant full-scan MS and MS/MS datasets were automatically processed through a combination of targeted and untargeted peak finding strategies.MS/MS spectra of predicted metabolites were interrogated against putative metabolite sequences,in light of a,b,y and internal fragment series.The resulting fragment assignments led to the confirmation and ranking of the metabolite sequences and identification of metabolic modification.As a result,29 metabolites with linear or cyclic structures were detected in the insulin incubation with the hydrolytic enzymes.Sequences of twenty insulin metabolites were further determined,which were consistent with the hydrolytic sites of these enzymes.In the same manner,multiple metabolites of insulin and ANP formed in rat liver S9 incubation were detected and structurally characterized,some of which have not been previously reported.The results demonstrated the utility of software-aided data processing tool in detection and identification of cyclic peptide metabolites.展开更多
[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were...[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L(r^2〉0.99).The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations(RSD)were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.展开更多
On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real tim...On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).展开更多
Aristolochic acid (AA) is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of ar...Aristolochic acid (AA) is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2′-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction (SPE), and further purified by a reversed-phase high performance liquid chromatography (HPLC). By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity (more than 94% as indicated by HPLC) were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry (LC-ESI-Q-TOF-MS/MS) and LC-Diode array detector-fluorescence (LC-DAD-FL) analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.展开更多
基金This work was financially supported by the National Key Research and Development Program of China(Grant No.2018YFC1704500)Tianjin Committee of Science and Technology of China(Grant No.21ZYJDJC00080)National Natural Science Foundation of China(Grant No.81872996).
文摘The complex composition of herbal metabolites necessitates the development of powerful analytical techniques aimed to identify the bioactive components.The seeds of Descurainia sophia(SDS)are utilized in China as a cough and asthma relieving agent.Herein,a dimension-enhanced integral approach,by combining ultra-high performance liquid chromatography/ion mobility-quadrupole time-of-flight mass spectrometry(UHPLC/IMQTOF-MS)and intelligent peak annotation,was developed to rapidly characterize the multicomponents from SDS.Good chromatographic separation was achieved within 38 min on a UPLC CSH C18(2.1×100 mm,1.7μm)column which was eluted by 0.1%formic acid in water(water phase)and acetonitrile(organic phase).Collision-induced dissociation-MS^(2)data were acquired by the data-independent high-definition MS^(E)(HDMS^(E))in both the negative and positive electrospray ionization modes.A major components knockout strategy was applied to improve the characterization of those minor ingredients by enhancing the injection volume.Moreover,a self-built chemistry library was established,which could be matched by the UNIFI software enabling automatic peak annotation of the obtained HDMS^(E)data.As a result of applying the intelligent peak annotation workflows and further confirmation process,a total of 53 compounds were identified or tentatively characterized from the SDS,including 29 flavonoids,one uridine derivative,four glucosides,one lignin,one phenolic compound,and 17 others.Notably,four-dimensional information related to the structure(e.g.,retention time,collision cross section,MS^(1)and MS^(2)data)was obtained for each component by the developed integral approach,and the results would greatly benefit the quality control of SDS.
基金Supported by Key R&D Projects in Hebei Province(19227516D)Hebei Provincial PhaseⅡModern Agricultural Industry Technology System Innovation Team Building Project(HBCT2018120207,HBCT2018160403)Hebei Province Innovation Ability Promotion Plan Project(20567673H)。
文摘Milk and dairy products are more and more popular with consumers due to their various nutrients, and their quality and safety issues have always been concerned. Therefore, the development of rapid, accurate and simple screening techniques is of great significance. Liquid chromatography-high resolution time-of-flight mass spectrometry has high-resolution and high-throughput detection functions, and has gradually begun to be applied in the detection of milk and dairy products. This paper summarized the application of milk and dairy products in liquid chromatography-high resolution time-of-flight mass spectrometry, laying a foundation for the development of new methods.
基金the Natural Science Foundation of Hunan Province, China (No. 05JJ40017).
文摘A An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of 24 elements (Be, Mg, A1, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn Sb, Ba, Pt, Au, and Pb) in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCI. The matrix effects because of the presence of excess HCI and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits were 0.016-1.50 ].tg·g^-1, the recovery ratios were 92.2%-111.2%, and the RSD was less than 3.6%. The method was accurate, quick, and convenient. It was applied to the determination of trace impurities in high purity cobalt with satisfactory results.
基金supported by the Natural Science Foundation of Hunan Province(No.05JJ40017)Education Department of Hunan Province(No.05B064).
文摘An analytical method using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS) for rapid simultaneous determination of Be, Mg, Al, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, As, Se, Mo, Ag, Cd, Sn, Sb, Ba, Pt, Au and Pb in high purity cobalt was described. Sample digestions were performed in closed microwave vessels using HNO3 and HCl. The matrix effects due to the presence of excess HCl and Co were evaluated. The usefulness of high mass resolution for overcoming some spectral interference was demonstrated. The optimum conditions for the determination was tested and discussed. Correction for matrix effects, Sc, Rh and Bi were used as internal standards. The detection limits is 0.003-0.57 μg/g, the recovery ratio is 92.2%-111.2%, and the RSD is less than 3.6%. The method is accurate, quick and convenient. It has been applied to the determination of trace impurities in high purity cobalt with satisfactory results.
文摘The determination of trace impurities in high purity zinc oxide by high resolution inductively coupled plasma mass spectrometry ( HR-ICP-MS ) was investigated. To overcome some poteutially problematic spectral iuterference, measurements were acquired in both middle and high resolution modes. The matrix effects due to the presence of excess HCl and zinc were evaluated. The optimum conditions for the determination were tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits ranged from 0.02μg/ g to 6 μg/ g depending on the elements. The experimental resalts for the determination of Na, Mg, Ca, Cr, Mn, Fe, Co, Ni, Cu, Mo, Cd, Sb and Pb in several high purity zinc oxide powders were presented.
基金Project(21075138) supported by the National Natural Science Foundation of ChinaProject(cstc2011jjA0780) supported by Natural Science Foundation of Chongqing City,ChinaProject(KJ121311) supported by Educational Commission of Chongqing City of China
文摘The contents of Mg,Al,Si,Ti,Cr,Mn,Fe,Co,Cu,Ga,As,Se,Cd,Sb,Pb and Bi in high purity nickel were determined by high resolution inductively coupled plasma mass spectrometry(HR-ICP-MS).The sample was dissolved in HNO3 and HCl by microwave digestion.Most of the spectral interferences could be avoided by measuring in the high resolution mode.The matrix effects because of the presence of excess HCl and nickel were evaluated.Correction for matrix effects was made using Sc,Rh and Tl as internal standards.The optimum conditions for the determination were tested and discussed.The detection limits range from 0.012 to 1.76 μg/g depending on the type of elements.The applicability of the proposed method is also validated by the analysis of high purity nickel reference material(NIST SRM 671).The relative standard deviation(RSD) is less than 3.3%.Results for determination of trace elements in high purity nickel were presented.
基金Funded by the Hunan Provincial Natural Science Foundation of China(No.05JJ40017)Hunan Provincial Education Department of China (No.07C029 , 08C260)
文摘Trace elements were determined in high purity gold by high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). Sample were decomposed by aqua regia. To overcome some potentially problematic spectra/ interference, measurements were acquired in both medium and high resolution modes. The matrix effects due to the presence of excessive HCl and Au were evaluated. The optimum conditions for the determination was tested and discussed. The standard addition method was employed for quantitative analysis. The detection limits range from 0.01ug/g to 0.28ug/g depending on the elements. The method is accurate, quick and convenient. It has been applied to the determination of trace elements in high purity gold with satisfactory results.
文摘Identification of novel specialized metabolites or bioactive compounds represents the main objective in the research field of natural product leads and drug discovery. Mass spectrometry (MS) provides a central tool to expedite and make more efficient the discovery and isolation phases, while minimizing the waste of resources on rediscovery of known compounds. MS contributes acutely to elucidation and identification of numerous species because it allows molecular mass and structural features determination. In particular, identification of the elemental composition of a precursor ion of interest by accurate mass measurement and investigation of dissociative processes undergone by the molecule, represent a worthy methodology to access the structure assignment. The aim of this study was to discover and identify novel antibacterial drugs from microbial source in a jungle of already known compounds. The focus of this paper is on the analytical strategy that permitted the disclosure of a new compound, otherwise confused with other substances. Emphasis is placed on the interpretation of the ESI-MS/MS fragmentation pattern that combined with high resolution mass determination, allowed step by step to properly deduce the exact molecular formula of an unknown component with a molecular weight higher than 1500 Daltons.
文摘This paper reported a new analytical method for the simultaneous determination of seven benzotriazole ultraviolet absorbers and seven antibacterial agents in textiles. After ultrasonic extraction for the textile samples in methanol, the solutions were analyzed by ultra-high performance liquid chromotagraphy/orbitrap high resolution mass spectrometry (UPLC/Orbitrap HRMS). It showed that a good chromatographic separation for these target compounds was achieved by a Hypersil GOLD column (100 mm × 2.1 mm × 1.9 μm) with a gradient elution of methanol and 0.1% aqueous formic acid solution (containing 0.5 mmol/L ammonium acetate). Triclosan and 4-chloro-3,5-dimethyl phenol (PCMX) were detected by the orbitrap HRMS in an electrospray ionization (ESI) negative mode while the other twelve target compounds were detected by orbitrap HRMS in ESI positive mode. Full scan experiment was performed over the range from m/z 100 to m/z 500. These target compounds were routinely detected with mass accuracy below 2 × 10-6 (2 ppm) at the optimized conditions. The results showed that the limits of detection (LODs) were in the range from 0.1 to 0.3 μg/kg. The blank samples were spiked at three levels and their average recoveries varied from 80.5% to 96.3% while the relative standard deviation (RSD) changed from 3.2% to 9.9%. The present method was also applied for the determination of those ultraviolet absorbers and antibacterial agents in the commercial textiles.
基金National Key R&D Program of China(No.2016YFF0203702)Quality Inspection Public Welfare Scientific Research Foundation of China(No.201310062)Science Research Program of General Administration of Quality Supervision,Inspection and Quarantine of China(No.2011IK037)
文摘Liquid chromatography coupled to high resolution mass spectrometry(LC-HRMS)was used to establish a high throughput and sensitive method for 18 phthalic acid esters(PAEs)in textiles.The method was applied to screen PAEs in 413 textile samples and 7 434 pieces of test data were analyzed.Further discussion was conducted about specific compounds,textile materials,detected value distribution and positive rate of samples.Twenty-nine percent of samples were detected with PAEs,and no samples were detected beyond regulations.Diisobutyl phthalate(DiBP),Dibutyl phthalate(DBP)and Di-2-ethylhexyl phthalate(DEHP)were detected with high frequency,and most samples were fabrics with coating and printing.This study can be used to reflect distribution of phthalate residues in textiles on the market and provide data support for risk assessment of PAEs for textile producers and consumers.
基金supported by the National Natural Science Foundation of China(Grant Nos.:81703463 and 81603277)the National Key R&D Program of China(Grant No.:U1508220)the Liaoning Distinguished Professor Project for Qing Li,and the Doctoral Scientific Research Foundation of Liaoning Province(Grant No.:20170520199).
文摘Pulmonary fibrosis(PF)is an irreversible lung disease that is characterized by excessive scar tissue with a poor median survival rate of 2-3 years.The inhibition of transforming growth factor-β receptor type-I(TGF-β RI)by an appropriate drug may provide a promising strategy for the treatment of this disease.Polygonum cuspidatum(PC)is a well-known traditional Chinese herbal medicine which has an anti-PF effect.Accordingly,a combination of high resolution mass spectrometry with an in silico strategy was developed as a new method to search for potential chemical ingredients of PC that target the TGF-β RI.Based on this strategy,a total of 24 ingredients were identified.Then,absorption,distribution,metabolism,and excretion(ADME)-related properties were subsequently predicted to exclude compounds with potentially undesirable pharmacokinetics behaviour.Molecular docking studies on TGF-β RI were adopted to discover new PF inhibitors.Eventually,a compound that exists in PC known as resveratrol was proven to have excellent biological activity on TGF-β RI,with an IC_(50) of 2.211 μM in vitro.Furthermore,the complex formed through molecular docking was tested via molecular dynamics simulations,which revealed that resveratrol had strong interactions with residues of TGF-β RI.This study revealed that resveratrol has significant potential as a treatment for PF due to its ability to target TGF-β RI.In addition,this research demonstrated the exploration of natural products with excellent biological activities toward specific targets via high resolution mass spectrometry in combination with in silico technology is a promising strategy for the discovery of novel drugs.
文摘Compared to their linear counterparts,cyclic peptides show better biological activities,such as antibacterial,immunosuppressive,and anti-tumor activities,and pharmaceutical properties due to their conformational rigidity.However,cyclic peptides could form numerous putative metabolites from potential hydrolytic cleavages and their fragments are very difficult to interpret.These characteristics pose a great challenge when analyzing metabolites of cyclic peptides by mass spectrometry.This study was to assess and apply a software-aided analytical workflow for the detection and structural characterization of cyclic peptide metabolites.Insulin and atrial natriuretic peptide(ANP)as model cyclic peptides were incubated with trypsin/chymotrypsin and/or rat liver S9,followed by data acquisition using TripleTOF?5600.Resultant full-scan MS and MS/MS datasets were automatically processed through a combination of targeted and untargeted peak finding strategies.MS/MS spectra of predicted metabolites were interrogated against putative metabolite sequences,in light of a,b,y and internal fragment series.The resulting fragment assignments led to the confirmation and ranking of the metabolite sequences and identification of metabolic modification.As a result,29 metabolites with linear or cyclic structures were detected in the insulin incubation with the hydrolytic enzymes.Sequences of twenty insulin metabolites were further determined,which were consistent with the hydrolytic sites of these enzymes.In the same manner,multiple metabolites of insulin and ANP formed in rat liver S9 incubation were detected and structurally characterized,some of which have not been previously reported.The results demonstrated the utility of software-aided data processing tool in detection and identification of cyclic peptide metabolites.
基金Supported by Scientific Research Projects of General Administration of Quality Supervision,Inspection and Quarantine“Standard Sample Development and Production System Construction of Animal-derived Veterinary Drugs”(20130143)
文摘[Objective]The research aimed to establish a liquid chromatography-high-resolution mass spectrometry for detecting residues of diclazuril,toltrazuril and its metabolites in animal-derived food.[Method]The samples were pre-treated by QuEChERS technology and detected by Exactive liquid chromatography-high resolution mass spectrometry.The liquid chromatography-high-resolution mass spectrometry for detecting the residues of diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food was established.[Result]Diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide showed a good linear correlation in the range of 2.0-50.0μg/L(r^2〉0.99).The average recoveries of these four compounds in bovine power at the spiked levels of 2,10 and 20μg/kg were 74.5%-90.1%,and the relative standard deviations(RSD)were 15.4%-17.5%.[Conclusion]This method was stable and reliable,and could be used to detect diclazuril,toltrazuril,toltrazuril sulfone and toltrazuril sulfoxide in animal-derived food.
基金supported by the National Natural Science Foundation of China(No.41805105)。
文摘On-line chemical characterization of atmospheric particulate matter(PM)with soft ionization technique and ultrahigh-resolution Mass Spectrometry(UHRMS)provides molecular information of organic constituents in real time.Here we describe the development and application of an automatic measurement system that incorporates PM_(2.5)sampling,thermal desorption,atmospheric pressure photoionization,and UHRMS analysis.Molecular formulas of detected organic compounds were deducted from the accurate(±10 ppm)molecular weights obtained at a mass resolution of 100,000,allowing the identification of small organic compounds in PM_(2.5).Detection efficiencies of 28 standard compounds were determined and we found a high sensitivity and selectivity towards organic amines with limits of detection below 10 pg.As a proof of principle,PM_(2.5)samples collected off-line in winter in the urban area of Beijing were analyzed using the Ionization Module and HRMS of the system.The automatic system was then applied to conduct on-line measurements during the summer time at a time resolution of 2 hr.The detected organic compounds comprised mainly CHON and CHN compounds below 350 m/z.Pronounced seasonal variations in elemental composition were observed with shorter carbon backbones and higher O/C ratios in summer than that in winter.This result is consistent with stronger photochemical reactions and thus a higher oxidation state of organics in summer.Diurnal variation in signal intensity of each formula provides crucial information to reveal its source and formation pathway.In summary,the automatic measurement system serves as an important tool for the on-line characterization and identification of organic species in PM_(2.5).
基金supported by the National Basic Research Program (973) of China (No. 2007CB407305,2008CB417201)the National High Technology Research and Development Program (863) of China (No.2007AA06A407)the National Natural Science Foundation of China (No. 20737003, 20621703, 20805057)
文摘Aristolochic acid (AA) is a known nephrotoxin and potential carcinogen, which can form covalent DNA adducts after metabolic activation in vivo and in vitro. A simple method for preparation and characterization of aristolochic acid-DNA adducts was developed. Four AA-adducts were synthesized by a direct reaction of AAI/AAII with 2′-deoxynucleosides. The reaction mixture was first cleaned-up and pre-concentrated using solid phase extraction (SPE), and further purified by a reversed-phase high performance liquid chromatography (HPLC). By the application of developed SPE procedure, matrices and byproducts in reaction mixture could be greatly reduced and adducts of high purity (more than 94% as indicated by HPLC) were obtained. The purified AA-DNA adducts were identified and characterized with liquid-electrospray ionization-quadrupole-time of flight-mass spectrometry (LC-ESI-Q-TOF-MS/MS) and LC-Diode array detector-fluorescence (LC-DAD-FL) analysis. This work provides a robust tool for possible large-scale preparation of AA-DNA adduct standards, which can promote the further studies on carcinogenic and mutagenic mechanism of aristolochic acids.