A combination of high-field asymmetric waveform ion mobility spectrometry （FAIMS） with mass spectrometer （MS） was analyzed. FAIMS separates ions from the volatile organic compounds in the gas-phase as an ion-filte...A combination of high-field asymmetric waveform ion mobility spectrometry （FAIMS） with mass spectrometer （MS） was analyzed. FAIMS separates ions from the volatile organic compounds in the gas-phase as an ion-filter for MS. The sample ions were created at ambient pressure by ion source, which was equipped with a 10.6 eV UV discharge lamp （A=116.5 nm）. The drift tube of FAIMS is composed of two parallel planar electrodes and the dimension is 10 mm×8 mm×0.5 mm. FAIMS was investigated when driven by the high-filed rectangular asymmetric waveform with the peak-to-peak voltage of 1.36 kV at the frequency of 1 MHz and the duty cycle of 30%. The acetone, the butanone, and their mixture were adopted to characterize the FAIMS-MS. The mass spectra obtained from MS illustrate that there are ion-molecular reactions between the ions and the sample neutral molecular. And the proton transfer behavior in the mixture of the acetone and the butanone is also observed. With the compensation voltage tuned from -30 V to 10 V with a step size of 0.1 V, the ion pre-separation before MS is realized.展开更多
An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-o...An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.展开更多
A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparatio...A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparation system （80 mL）, a CO2 laser for heating samples, a crusher for extracting fluid inclusions within K-poor minerals and an air reservoir （31 L） and pipette （0.1 mL） system. The ARGUS VI mass spectrometer is operated by the Qtegra Noble Gas software, which can control the peripheral accessories, such as pneumatic valves, CO2 laser and crusher through a PeriCon （peripheral controller）. The experimental procedures of atmospheric argon ana- lyses, ^40Ar/^39Ar dating by laser stepwise heating and by progressive crushing in vacuo, can be fully automatically performed. The weighted mean of atmospheric ^40Ar/^36Ar ratios is 302.22＋0.03 （1σ, MSWD=0.74, n=200）, indicating that air reservoir and pipette system and the whole instrument sys- tem are very stable. This laboratory is a successful pioneer example in China to establish a new no- ble gas laboratory with self-made peripheral accessories expect for the mass spectrometer.展开更多
With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years...With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.展开更多
Fine particle of organic aerosol （OA）, mostly arising from pollution, are abundant in Beijing. To achieve a better un- derstanding of the difference in OA in summer and autumn, a high-resolution time-of-flight aeros...Fine particle of organic aerosol （OA）, mostly arising from pollution, are abundant in Beijing. To achieve a better un- derstanding of the difference in OA in summer and autumn, a high-resolution time-of-flight aerosol mass spectrometer （HR- ToF-AMS, Aerodyne Research Inc., USA） was deployed in urban Beijing in August and October 2012. The mean OA mass concentration in autumn was 30 4-30 μg m-3, which was higher than in summer （13 4-6.9 μg m-3）. The elemental anal- ysis found that OA was more aged in summer （oxygen-to-carbon （O/C） ratios were 0.41 and 0.32 for summer and autumn, respectively）. Positive matrix factorization （PMF） analysis identified three and five components in summer and autumn, re- spectively. In summer, an oxygenated OA （OOA）, a cooking-emission-related OA （COA）, and a hydrocarbon-like OA （HOA） were indentified. Meanwhile, the OOA was separated into LV-OOA （low-volatility OOA） and SV-OOA （semi-volatile OOA）; and in autumn, a nitrogen-containing OA （NOA） was also found. The SOA （secondary OA） was always the most important OA component, accounting for 55% of the OA in the two seasons. Back trajectory clustering analysis found that the origin of the air masses was more complex in summer. Southerly air masses in both seasons were associated with the highest OA loading, while northerly air masses were associated with the lowest OA loading. A preliminary study of OA components, especially the POA （primary OA）, in different periods found that the HOA and COA all decreased during the National Day holiday period, and HOA decreased at weekends compared with weekdays.展开更多
We introduce a modification of reflectron time-of-flight mass spectrometer for laser photodissociation of mass-selected ions. In our apparatus, the ions of interests were selected by a mass gate near the first space f...We introduce a modification of reflectron time-of-flight mass spectrometer for laser photodissociation of mass-selected ions. In our apparatus, the ions of interests were selected by a mass gate near the first space focus point and decelerated right after the mass gate, were then crossed by a laser beam for dissociation. The daughter ions and surviving parent ions were re-accelerated and analyzed by the reflectron time-of-flight mass spectrometer. Compared to the designs reported by other research groups, our selection-deceleration-dissociation-reacceleration approach has better daughter-parent-ions-separation, easier laser timing, and better overlapping between the ion beam and laser beam. We also conducted detailed cal- culations on the parent ion and daughter ion flight times, and provided a simplified formula for the calibration of daughter ion mass.展开更多
Two different aerosol mass spectrometers, Aerodyne Aerosol Mass Spectrometer（AMS） and Single Particle Aerosol Mass Spectrometer（SPAMS） were deployed to identify the aerosol pollutants over Xiamen, representing the...Two different aerosol mass spectrometers, Aerodyne Aerosol Mass Spectrometer（AMS） and Single Particle Aerosol Mass Spectrometer（SPAMS） were deployed to identify the aerosol pollutants over Xiamen, representing the coastal urban area. Five obvious processes were classified during the whole observation period. Organics and sulfate were the dominant components in ambient aerosols over Xiamen. Most of the particles were in the size range of 0.2–1.0 μm, accounting for over 97% of the total particles measured by both instruments.Organics, as well as sulfate, measured by AMS were in good correlation with measured by SPAMS. However, high concentration of NH4＋was obtained by AMS, while extremely low value of NH4＋was detected by SPAMS. Contrarily, high particle number counts of NO3-and Clwere given by SPAMS while low concentrations of NO3-and Cl-were measured by AMS. The variations of POA and SOA obtained from SPAMS during event 1 and event 2 were in accordance with the analysis of HOA and OOA given by AMS, suggesting that both of AMS and SPAMS can well identify the organic clusters of aerosol particles. Overestimate or underestimate of the aerosol sources and acidity would be present in some circumstances when the measurement results were used to analyze the aerosol properties, because of the detection loss of some species for both instruments.展开更多
Benzene is a major industrial air pollutant and can cause serious human health disorders. In this paper an investigation on benzene destruction, in an atmospheric-pressure fast-flow pulsed DC-discharge by means of las...Benzene is a major industrial air pollutant and can cause serious human health disorders. In this paper an investigation on benzene destruction, in an atmospheric-pressure fast-flow pulsed DC-discharge by means of laser ionization combined with time-of-flight （TOF） mass spectrometry, is reported. Most by-products including transient reactive species from the benzene discharge were characterized by molecular beam sampling combined with TOF mass spectrometry. It is showed that, with a gas mixture of 0.5% C6H6 in Ar, benzene can be effectively destroyed by discharge plasma. The intermediate species consisted of small fragments of CnHm （n=3-5, m = 1-11）, cycle-chain species of CnHm （n =6-9, m = 7-10） and polycyclic species CnHm （n ≥9, m = 8-12）. The alternation of mass peaks （intensity） with even/odd electrons was observed in the measured mass spectra. The results indicated that the alternation is mainly due to the different ionization potentials of the open shell and close shell species. Based on the examination of the features of the species＇ composition, the primary reaction pathways are proposed and discussed.展开更多
It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency f...It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency field enhanced chemical ionization source （RF-ECI） with vacuum ultraviolet （VUV）lamp by coupling radiofrequency electric field and direct-current field together. The experiment resultsshowed that the sensitivity of benzene, toluene, hydrogen sulfide and other compounds increased by 2-3orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization（SPI）. At the same time, the reagent ion of O2＋ realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp hasinherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-of-flight mass spectrometer （TOFMS） has a limit-of-detection for H2S as low as 0.0571 mg/m3, and it is expected to be used widely in the field of on-site rapidanalvsis.展开更多
Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and...Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and their possible structures were discussed.The results indicated that C60 is very reactive to electrophiles in the gas phase.展开更多
New particle formation(NPF)is the primary source of nanoparticles and contributes a large number of concentrations of cloud condensation nuclei.In recent years,field campaigns and laboratory experiments have been cond...New particle formation(NPF)is the primary source of nanoparticles and contributes a large number of concentrations of cloud condensation nuclei.In recent years,field campaigns and laboratory experiments have been conducted to promote cognition of the mechanism for NPF and its following growth processes.The chemical composition measurement of nanoparticles could help deepen understanding of the initial step of particulate matter formation.In this work,we developed a nanoparticle chemical ionization mass spectrometer to measure nanoparticles’chemical compositions during their initial growth stage.Meanwhile,a non-radioactive ion source was designed for aerosol charging and chemical ionization.Time of flight mass spectrometer coupled with integrated aerosol size selection and collection module would guarantee the picogram level detection limit and high-resolution ability to measure the matrix of ambient samples.The performance of this equipment was overall evaluated,including the transmission efficiency and collection efficiency of custombuilt nano differential mobility analyzer,chemical ionization efficiency,and mass resolution of the mass spectrometer.The high sensitivity measurement of ammonium sulfate and methylammonium sulfate aerosols with diameters ranging from 10 to 25 nm could guarantee the application of this instrument in the ambient measurement.展开更多
Phospholipids are the major building blocks of the biological membranes. Additionally, phospholipids modulate membrane trafficking and metabolites derived from their
A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main featur...A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main features of our designed spectrometer involve the coupling of a liquid microjet nozzle to a conventional ion optics and the application of femtosecond pulses for mass spectral ionization.The detailed design,construction,and simulation of this new spectrometer are presented.More importantly,we combined the experimental tests with the simulated electric fields and ion trajectories to investigate the performance of the designed spectrometer,especially the kind of disturbances of the nozzle electric field on the conventional ion optics.In our current design,the optimal E/R(E:extractor,R:repeller)electrode voltage ratio was found to be∼0.71 when the voltages on the R,E and G(ground)electrodes were set to be 1500,1060 and 0 V,respectively,whilst the voltage on the N nozzle electrode was required to be around 1250 V.The capability of the designed spectrometer has been demonstrated by recording the simulated mass spectra of the water,benzene and cytidine with their mass/charge ratios of 18,76 and 243,respectively.This work shall be helpful for the development of new all-liquid-phase mass spectral technology to be employed in the diagnosis of diseases by the mass analysis of human body fluids.展开更多
The mass resolution of the ordinary ion trap mass spectrometer derived from the quadrupole mass spectrometer usually ranges from hundreds to thousands.In this study,the fine secular frequency resonance oscillation was...The mass resolution of the ordinary ion trap mass spectrometer derived from the quadrupole mass spectrometer usually ranges from hundreds to thousands.In this study,the fine secular frequency resonance oscillation was observed with a rectilinear ion trap mass spectrometer.The FWHM of the responding resonance secular frequency of benzene was 0.012 kHz.The corresponding mass resolution was 8600 m/Δm for benzene(m/z=78).The mass spectrometer with secular frequency scanning has a linear response to benzene in the concentration range from 200 ppbv to 10000 ppbv.This study shows a new feature of the secular frequency scanning for ion trap mass spectrometers.展开更多
Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then det...Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.展开更多
A simultaneous method was successfully established and validated for the separation and determination of bu- prenorphine （BP）, its primary metabolite, nor-buprenorphine （NBP） and a proposed co-formulate, naloxone ...A simultaneous method was successfully established and validated for the separation and determination of bu- prenorphine （BP）, its primary metabolite, nor-buprenorphine （NBP） and a proposed co-formulate, naloxone （NLX） in human plasma. The method used buprenorphine-d4 （BP-D4）, nor-buprenorphine-d3 （NBP-D3）, naltrexone （NTX） as internal standards （ISs）. 100 μL of plasma sample fortified with the ISs was cleaned up by solid-phase extraction （SPE）, and was then separated on a Waters AcquityTM BEH C18 column with gradient elution using methanol and water （containing 0.2% formic） at a flow rate of 0.25 mL·min^-1. The mass spectrometer was used for detection and was operated in the positive electrospray ionization with multiple reaction monitoring （MRM） mode. The three compounds were effectively separated in 5 min. The linear ranges of the compounds were 0.1--25, 0.25--25 and 0.05--25 ng·mL^-1 for BP, NBP and NLX, respectively, with r≥0.9935. The method had high sensitivity （the lim- its of detection were 0.02, 0.1 and 0.01 ng.mL-1 for BP, NBP and NLX, respectively） and high recoveries （≥97.6%）. The result was shown to be linear and satisfactorily met current acceptance criteria for validation of bio- analytical method： intra and inter assay precisions within the required limits of ≤25% RSD. The LOQs fulfilled the LOQ requirements： precision≤25% RSD, and was fully validated according to the State Food and Drug Administration （SFDA） regulations. The results demonstrated that ultra-high performance liquid chromatography- tandem mass spectrometer （UPLC-MS/MS） with SPE was a powerful detection tool and contributed to pharmaceutical analysis in biological matrices.展开更多
Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chro...Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.展开更多
An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed la...An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.展开更多
Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haz...Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haze,remains very scarce.This study used single-particle aerosol mass spectrometry to investigate IM-containing particles in Chengdu,one of the megacities in the SCB,during summer and winter before and after implemen-tation of the Three-year Action Plan to Win the Blue-Sky Defense War(BSDW).We found that IM-containing particles accounted for 1.2%–12.0%of all detected particles,and they highly mixed with carbonaceous com-ponents,secondary inorganic species,and organic nitrogen.From before to after the BSDW,the proportion of IM-containing particles decreased by 1.8%in summer,but increased by 9.6%in winter.Ammonium/amines and carbonyl compounds were closely related to IM-containing particles;the highest proportion of IM-containing particles occurred in particles mixed with amines and carbonyls.The number fraction of IM-containing particles in all seasons was higher at night than during daytime.The potential source areas of IM-containing particles showed notable narrowing after the BSDW,and the high-value areas were found distributed closer to Chengdu and its surrounding areas.In the winter before the BSDW,most IM-containing particles(>70%)were mixed with organic carbon(OC)particles,and the contributions of OC and mixed organic–elemental carbon(OC-EC)particles increased with aggravation of pollution,whereas OC-EC and Metal particles played a more crucial role in the winter after the BSDW.展开更多
As one of the major volatile components in extraterrestrial materials,nitrogen(N_(2))isotopes serve not only as tracers for the formation and evolution of the solar system,but also play a critical role in assessing pl...As one of the major volatile components in extraterrestrial materials,nitrogen(N_(2))isotopes serve not only as tracers for the formation and evolution of the solar system,but also play a critical role in assessing planetary habitability and the search for extraterrestrial life.The integrated measurement of N_(2)and argon(Ar)isotopes by using noble gas mass spectrometry represents a state-of-the-art technique for such investigations.To support the growing demands of planetary science research in China,we have developed a high-efficiency,high-precision method for the integrated analysis of N_(2)and Ar isotopes.This was achieved by enhancing gas extraction and purification systems and integrating them with a static noble gas mass spectrometer.This method enables integrated N_(2)-Ar isotope measurements on submilligram samples,significantly improving sample utilization and reducing the impact of sample heterogeneity on volatile analysis.The system integrates CO_(2)laser heating,a modular two-stage Zr-Al getter pump,and a CuO furnace-based purification process,effectively reducing background levels(N_(2)blank as low as 0.35×10^(−6)cubic centimeters at standard temperature and pressure[ccSTP]).Analytical precision is ensured through calibration with atmospheric air and CO corrections.To validate the reliability of the method,we performed N_(2)-Ar isotope analyses on the Allende carbonaceous chondrite,one of the most extensively studied meteorites internationally.The measured N_(2)concentrations range from 19.2 to 29.8 ppm,withδ15N values between−44.8‰and−33.0‰.Concentrations of 40Ar,36Ar,and 38Ar are(12.5-21.1)×10^(−6)ccSTP/g,(90.9-150.3)×10^(−9)ccSTP/g,and(19.2-30.7)×10^(−9)ccSTP/g,respectively.These values correspond to cosmic-ray exposure ages of 4.5-5.7 Ma,consistent with previous reports.Step-heating experiments further reveal distinct release patterns of N and Ar isotopes,as well as their associations with specific mineral phases in the meteorite.In summary,the combined N_(2)-Ar isotopic system offers significant advantages for tracing volatile sources in extraterrestrial materials and will provide essential analytical support for upcoming Chinese planetary missions,such as Tianwen-2.展开更多
文摘A combination of high-field asymmetric waveform ion mobility spectrometry （FAIMS） with mass spectrometer （MS） was analyzed. FAIMS separates ions from the volatile organic compounds in the gas-phase as an ion-filter for MS. The sample ions were created at ambient pressure by ion source, which was equipped with a 10.6 eV UV discharge lamp （A=116.5 nm）. The drift tube of FAIMS is composed of two parallel planar electrodes and the dimension is 10 mm×8 mm×0.5 mm. FAIMS was investigated when driven by the high-filed rectangular asymmetric waveform with the peak-to-peak voltage of 1.36 kV at the frequency of 1 MHz and the duty cycle of 30%. The acetone, the butanone, and their mixture were adopted to characterize the FAIMS-MS. The mass spectra obtained from MS illustrate that there are ion-molecular reactions between the ions and the sample neutral molecular. And the proton transfer behavior in the mixture of the acetone and the butanone is also observed. With the compensation voltage tuned from -30 V to 10 V with a step size of 0.1 V, the ion pre-separation before MS is realized.
文摘An experiment facility has been set up for the study of metal cluster compounds in our laboratory, which consists of a nano-electrospray ionization source, an ion transmission and focus system, and a reflectron time-of-fight mass spectrometer. Taking advantage of the nano-electrospray ionization source, polyvalent ions are usually produced in the ＂ionization＂ process and the obtained mass resolution of the equipment is over 8000. The molecular ion peaks of metal cluster compounds [Au20（PPhpy2）10Cl2]（SbF6）4, where PPhpy2=bis（2- pyridyl）phenylphosphine, and [AuaAg2（C）L6]（BF4）4, where L=2-（diphenylphosphino）-5- methylpyridine, are distinguished in the respective mass spectrum, accompanied by some fragment ion peaks. In addition, the mass-to-charge ratios of the parent ions are determi- nated. Preliminary results suggest that the device is a powerful tool for the study of metal cluster compounds. It turns out that the information obtained by the instrumentation serves as an essential supplement to single crystal X-ray diffraction for structure characterization of metal cluster compounds.
基金financially supported by the National Natural Science Foundation of China (Nos. 41503053, 41630315, 41688103, and 91128203)
文摘A new fully automatic ^40Ar/^39Ar laboratory with a Thermo Scientific ARGUS VI mass spectrometer has been established in China University of Geosciences （Wuhan）. We designed and developed a mini efficient preparation system （80 mL）, a CO2 laser for heating samples, a crusher for extracting fluid inclusions within K-poor minerals and an air reservoir （31 L） and pipette （0.1 mL） system. The ARGUS VI mass spectrometer is operated by the Qtegra Noble Gas software, which can control the peripheral accessories, such as pneumatic valves, CO2 laser and crusher through a PeriCon （peripheral controller）. The experimental procedures of atmospheric argon ana- lyses, ^40Ar/^39Ar dating by laser stepwise heating and by progressive crushing in vacuo, can be fully automatically performed. The weighted mean of atmospheric ^40Ar/^36Ar ratios is 302.22＋0.03 （1σ, MSWD=0.74, n=200）, indicating that air reservoir and pipette system and the whole instrument sys- tem are very stable. This laboratory is a successful pioneer example in China to establish a new no- ble gas laboratory with self-made peripheral accessories expect for the mass spectrometer.
基金supported by the National Natural Science Foundation of China (Nos. 21475010, 61635003)Beijing Natural Science Foundation (No. 16L00065)State Key Laboratory Explosion Science and Technology (No. YBKT16-17)
文摘With outstanding analytical performance and portability, miniature mass spectrometer is one of the most powerful tools for in-situ analysis. The miniaturization of mass spectrometers has lasted for more than ten years, during which a number of miniature mass spectrometers employing different techniques have been developed. Small-in-size, working at relatively high pressure region and capable of performing tandem mass spectrometry, ion trap is the most widely used mass analyzer in miniature mass spectrometer systems. The recent development of miniature ion trap mass spectrometer systems in the last ten years was reviewed in this paper. These instruments adopt different atmospheric pressure interfaces （APIs）, which are membrane inlets （MIs）, discontinuous atmospheric pressure interface （DAPI） and continuous atmospheric pressure interface （CAPI）. This review emphasizes on the mini mass spectrometry （MS） system that can be handheld by one person, but not the field-able ones that are too large to be hand-portable.
基金supported by the "Strategic Priority Research Program" of the Chinese Academy of Sciences (Grant No. XDA05100100&XDB05020000)the National Natural Science Foundation of China (Grant Nos. 41230642 & 41275139)
文摘Fine particle of organic aerosol （OA）, mostly arising from pollution, are abundant in Beijing. To achieve a better un- derstanding of the difference in OA in summer and autumn, a high-resolution time-of-flight aerosol mass spectrometer （HR- ToF-AMS, Aerodyne Research Inc., USA） was deployed in urban Beijing in August and October 2012. The mean OA mass concentration in autumn was 30 4-30 μg m-3, which was higher than in summer （13 4-6.9 μg m-3）. The elemental anal- ysis found that OA was more aged in summer （oxygen-to-carbon （O/C） ratios were 0.41 and 0.32 for summer and autumn, respectively）. Positive matrix factorization （PMF） analysis identified three and five components in summer and autumn, re- spectively. In summer, an oxygenated OA （OOA）, a cooking-emission-related OA （COA）, and a hydrocarbon-like OA （HOA） were indentified. Meanwhile, the OOA was separated into LV-OOA （low-volatility OOA） and SV-OOA （semi-volatile OOA）; and in autumn, a nitrogen-containing OA （NOA） was also found. The SOA （secondary OA） was always the most important OA component, accounting for 55% of the OA in the two seasons. Back trajectory clustering analysis found that the origin of the air masses was more complex in summer. Southerly air masses in both seasons were associated with the highest OA loading, while northerly air masses were associated with the lowest OA loading. A preliminary study of OA components, especially the POA （primary OA）, in different periods found that the HOA and COA all decreased during the National Day holiday period, and HOA decreased at weekends compared with weekdays.
基金V. ACKNOWLEDGMENTS This work supported by the National Natural Science Foundation of China （No.20853001）. We thank Professor Qi-he Zhu and Professor Zhen Gao for valuable discussions.
文摘We introduce a modification of reflectron time-of-flight mass spectrometer for laser photodissociation of mass-selected ions. In our apparatus, the ions of interests were selected by a mass gate near the first space focus point and decelerated right after the mass gate, were then crossed by a laser beam for dissociation. The daughter ions and surviving parent ions were re-accelerated and analyzed by the reflectron time-of-flight mass spectrometer. Compared to the designs reported by other research groups, our selection-deceleration-dissociation-reacceleration approach has better daughter-parent-ions-separation, easier laser timing, and better overlapping between the ion beam and laser beam. We also conducted detailed cal- culations on the parent ion and daughter ion flight times, and provided a simplified formula for the calibration of daughter ion mass.
基金supported by the Natural Science Foundation of Fujian Province,China(No.2015J05024)financially supported by Qingdao National Laboratory for marine science and technology(No.QNLM2016ORP0109)+2 种基金the National Natural Science Foundation of China(No.21106018,No.41305133)the Scientific Research Foundation of Third Institute of Oceanography,SOA(No.2014027)the Special Fund for Marine Researches in the Public Interest(No.2004DIB5J178)
文摘Two different aerosol mass spectrometers, Aerodyne Aerosol Mass Spectrometer（AMS） and Single Particle Aerosol Mass Spectrometer（SPAMS） were deployed to identify the aerosol pollutants over Xiamen, representing the coastal urban area. Five obvious processes were classified during the whole observation period. Organics and sulfate were the dominant components in ambient aerosols over Xiamen. Most of the particles were in the size range of 0.2–1.0 μm, accounting for over 97% of the total particles measured by both instruments.Organics, as well as sulfate, measured by AMS were in good correlation with measured by SPAMS. However, high concentration of NH4＋was obtained by AMS, while extremely low value of NH4＋was detected by SPAMS. Contrarily, high particle number counts of NO3-and Clwere given by SPAMS while low concentrations of NO3-and Cl-were measured by AMS. The variations of POA and SOA obtained from SPAMS during event 1 and event 2 were in accordance with the analysis of HOA and OOA given by AMS, suggesting that both of AMS and SPAMS can well identify the organic clusters of aerosol particles. Overestimate or underestimate of the aerosol sources and acidity would be present in some circumstances when the measurement results were used to analyze the aerosol properties, because of the detection loss of some species for both instruments.
基金supported by National Natural Science Foundation of China (No. 10875023)Scientific and Technical Key Project of Educational Ministry of China (No. 108034)
文摘Benzene is a major industrial air pollutant and can cause serious human health disorders. In this paper an investigation on benzene destruction, in an atmospheric-pressure fast-flow pulsed DC-discharge by means of laser ionization combined with time-of-flight （TOF） mass spectrometry, is reported. Most by-products including transient reactive species from the benzene discharge were characterized by molecular beam sampling combined with TOF mass spectrometry. It is showed that, with a gas mixture of 0.5% C6H6 in Ar, benzene can be effectively destroyed by discharge plasma. The intermediate species consisted of small fragments of CnHm （n=3-5, m = 1-11）, cycle-chain species of CnHm （n =6-9, m = 7-10） and polycyclic species CnHm （n ≥9, m = 8-12）. The alternation of mass peaks （intensity） with even/odd electrons was observed in the measured mass spectra. The results indicated that the alternation is mainly due to the different ionization potentials of the open shell and close shell species. Based on the examination of the features of the species＇ composition, the primary reaction pathways are proposed and discussed.
基金financially supported by the National Natural Science Foundation of China(Nos.21375129 and 21675155)
文摘It is difficult to rapidly and on-line detect trace volatile organic compounds for miniature massspectrometry due to its limited sampling volume at slow pumping speed. In this paper, we developed anew radiofrequency field enhanced chemical ionization source （RF-ECI） with vacuum ultraviolet （VUV）lamp by coupling radiofrequency electric field and direct-current field together. The experiment resultsshowed that the sensitivity of benzene, toluene, hydrogen sulfide and other compounds increased by 2-3orders of magnitude under the introduction of RF-ECI comparing to traditional single photon ionization（SPI）. At the same time, the reagent ion of O2＋ realized the charge transfer reaction chemical ionization,and the RF-ECI effectively expanded the detection range of the VUV lamp based SPI. The VUV lamp hasinherent advantages in the on-site analytical instrument for its small size and low power consumption,and the VUV lamp based RF-ECI miniature time-of-flight mass spectrometer （TOFMS） has a limit-of-detection for H2S as low as 0.0571 mg/m3, and it is expected to be used widely in the field of on-site rapidanalvsis.
文摘Reactions of C60 with Si(CH_3)_nCl_(4-n) (n=2,3)in the ion source of the mass spectrometer have been studied.The corresponding adduct ions[C60Si(CH_3)_mCl3_(-m)]^+(m=1,2,3),[C60SiCl]^+ and[C60CH_3]^+ were observed and their possible structures were discussed.The results indicated that C60 is very reactive to electrophiles in the gas phase.
基金supported by the National Key Research and Development Program of China(No.2017YFC0209500)the National Natural Science Foundation of China(No.41822703)the Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXXM-202011)
文摘New particle formation(NPF)is the primary source of nanoparticles and contributes a large number of concentrations of cloud condensation nuclei.In recent years,field campaigns and laboratory experiments have been conducted to promote cognition of the mechanism for NPF and its following growth processes.The chemical composition measurement of nanoparticles could help deepen understanding of the initial step of particulate matter formation.In this work,we developed a nanoparticle chemical ionization mass spectrometer to measure nanoparticles’chemical compositions during their initial growth stage.Meanwhile,a non-radioactive ion source was designed for aerosol charging and chemical ionization.Time of flight mass spectrometer coupled with integrated aerosol size selection and collection module would guarantee the picogram level detection limit and high-resolution ability to measure the matrix of ambient samples.The performance of this equipment was overall evaluated,including the transmission efficiency and collection efficiency of custombuilt nano differential mobility analyzer,chemical ionization efficiency,and mass resolution of the mass spectrometer.The high sensitivity measurement of ammonium sulfate and methylammonium sulfate aerosols with diameters ranging from 10 to 25 nm could guarantee the application of this instrument in the ambient measurement.
文摘Phospholipids are the major building blocks of the biological membranes. Additionally, phospholipids modulate membrane trafficking and metabolites derived from their
基金supported by the Knowledge Innovation Program of Wuhan-Basic Research(Nos.2023020201010084,2022010801010134)the National Key Research and Development Program of China(No.2019YFA0307700)the National Natural Science Foundation of China(Nos.12274418,22273116,12074389,11974381,22363011).
文摘A liquid-microjet(LJ)linear time-of-flight(TOF)mass spectrometer,coupled with a femtosecond laser ionization source,has been designed for direct measurements of mass spectra of liquid aqueous solutions.Two main features of our designed spectrometer involve the coupling of a liquid microjet nozzle to a conventional ion optics and the application of femtosecond pulses for mass spectral ionization.The detailed design,construction,and simulation of this new spectrometer are presented.More importantly,we combined the experimental tests with the simulated electric fields and ion trajectories to investigate the performance of the designed spectrometer,especially the kind of disturbances of the nozzle electric field on the conventional ion optics.In our current design,the optimal E/R(E:extractor,R:repeller)electrode voltage ratio was found to be∼0.71 when the voltages on the R,E and G(ground)electrodes were set to be 1500,1060 and 0 V,respectively,whilst the voltage on the N nozzle electrode was required to be around 1250 V.The capability of the designed spectrometer has been demonstrated by recording the simulated mass spectra of the water,benzene and cytidine with their mass/charge ratios of 18,76 and 243,respectively.This work shall be helpful for the development of new all-liquid-phase mass spectral technology to be employed in the diagnosis of diseases by the mass analysis of human body fluids.
基金supported by the National Natural Science Foundation of China(No.22076184)Fundamental Research Funds for the Central Universities,Beijing Municipal Science&Technology Commission(Z181100003818008).
文摘The mass resolution of the ordinary ion trap mass spectrometer derived from the quadrupole mass spectrometer usually ranges from hundreds to thousands.In this study,the fine secular frequency resonance oscillation was observed with a rectilinear ion trap mass spectrometer.The FWHM of the responding resonance secular frequency of benzene was 0.012 kHz.The corresponding mass resolution was 8600 m/Δm for benzene(m/z=78).The mass spectrometer with secular frequency scanning has a linear response to benzene in the concentration range from 200 ppbv to 10000 ppbv.This study shows a new feature of the secular frequency scanning for ion trap mass spectrometers.
基金This work was supported by Academia Sinica Resource and Environment Project (Grant No.KZ951-B1-404). The experiment and analysis were carried out in the Institute of Geology and Geophysics, Chinese Academy of Sciences. The authors appreciate Prof. Kuro
文摘Quadrupole mass spectrometer (QMS) is an instrument for effectively determining gaseous composition of fluid inclusion. The gaseous component is extracted from inclusions with thermal decrepitation method and then determined with the sensitive QMS instrument. The method is characterized by high sensitivity and high accuracy with the relative standard deviation (RSD,n=6) of less than 3%. It has been successfully used for analyzing fluid inclusions. The analytical results meet the requirement of geological study.
文摘A simultaneous method was successfully established and validated for the separation and determination of bu- prenorphine （BP）, its primary metabolite, nor-buprenorphine （NBP） and a proposed co-formulate, naloxone （NLX） in human plasma. The method used buprenorphine-d4 （BP-D4）, nor-buprenorphine-d3 （NBP-D3）, naltrexone （NTX） as internal standards （ISs）. 100 μL of plasma sample fortified with the ISs was cleaned up by solid-phase extraction （SPE）, and was then separated on a Waters AcquityTM BEH C18 column with gradient elution using methanol and water （containing 0.2% formic） at a flow rate of 0.25 mL·min^-1. The mass spectrometer was used for detection and was operated in the positive electrospray ionization with multiple reaction monitoring （MRM） mode. The three compounds were effectively separated in 5 min. The linear ranges of the compounds were 0.1--25, 0.25--25 and 0.05--25 ng·mL^-1 for BP, NBP and NLX, respectively, with r≥0.9935. The method had high sensitivity （the lim- its of detection were 0.02, 0.1 and 0.01 ng.mL-1 for BP, NBP and NLX, respectively） and high recoveries （≥97.6%）. The result was shown to be linear and satisfactorily met current acceptance criteria for validation of bio- analytical method： intra and inter assay precisions within the required limits of ≤25% RSD. The LOQs fulfilled the LOQ requirements： precision≤25% RSD, and was fully validated according to the State Food and Drug Administration （SFDA） regulations. The results demonstrated that ultra-high performance liquid chromatography- tandem mass spectrometer （UPLC-MS/MS） with SPE was a powerful detection tool and contributed to pharmaceutical analysis in biological matrices.
基金funded by the Science and Technology Development Fund,Macao SAR(File no.0023/2019/AKP)Guangxi Science and Technology Department Fund(File no.AD17195002)。
文摘Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.
基金supported by the Ministry of Science and Technology of China(2013CB834603,2012YQ220113-3,and 2011YQ06010003)the National Natural Science Foundation of China(21273045 and 20933030)the Committee of Science and Technology of Shanghai(13XD1400800)
文摘An apparatus based on collinear tandem time-of-flight mass spectrometer has been designed for the measurement of infrared photodissociation spectroscopy of mass-selected ions in the gas phase.The ions from a pulsed laser vaporization supersonic ion source are skimmed and mass separated by a Wiley-McLaren time-of-flight mass spectrometer.The ion of interest is mass selected,decelerated and dissociated by a tunable IR laser.The fragment and parent ions are reaccelerated and mass analyzed by the second time-of-flight mass spectrometer.A simple new assembly integrated with mass gate,deceleration and reacceleration ion optics was designed,which allows us to measure the infrared spectra of mass selected ions with high sensitivity and easy timing synchronization.
基金supported by Sichuan Science and Technology Program(No.2024NSFSC0060)the National Natural Science Foundation of China(No.U23A2030)the Basic Research Cultivation Support Plan of Southwest Jiaotong University(No.2682023ZTPY016).
文摘Imidazole(IM)particles in the atmosphere affect climate,atmospheric chemical reactions,and human health.However,research on IM particles in the Sichuan Basin(SCB),one of the areas of China affected most heavily by haze,remains very scarce.This study used single-particle aerosol mass spectrometry to investigate IM-containing particles in Chengdu,one of the megacities in the SCB,during summer and winter before and after implemen-tation of the Three-year Action Plan to Win the Blue-Sky Defense War(BSDW).We found that IM-containing particles accounted for 1.2%–12.0%of all detected particles,and they highly mixed with carbonaceous com-ponents,secondary inorganic species,and organic nitrogen.From before to after the BSDW,the proportion of IM-containing particles decreased by 1.8%in summer,but increased by 9.6%in winter.Ammonium/amines and carbonyl compounds were closely related to IM-containing particles;the highest proportion of IM-containing particles occurred in particles mixed with amines and carbonyls.The number fraction of IM-containing particles in all seasons was higher at night than during daytime.The potential source areas of IM-containing particles showed notable narrowing after the BSDW,and the high-value areas were found distributed closer to Chengdu and its surrounding areas.In the winter before the BSDW,most IM-containing particles(>70%)were mixed with organic carbon(OC)particles,and the contributions of OC and mixed organic–elemental carbon(OC-EC)particles increased with aggravation of pollution,whereas OC-EC and Metal particles played a more crucial role in the winter after the BSDW.
基金supported by the Bureau of Frontier Sciences and Basic Research,Chinese Academy of Sciences(Grant No.QYJ-2025-0103)the National Natural Science Foundation of China(Grant Nos.42441834,42241105,42441825,and 42203048)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(Grant No.IGGCAS-202401).
文摘As one of the major volatile components in extraterrestrial materials,nitrogen(N_(2))isotopes serve not only as tracers for the formation and evolution of the solar system,but also play a critical role in assessing planetary habitability and the search for extraterrestrial life.The integrated measurement of N_(2)and argon(Ar)isotopes by using noble gas mass spectrometry represents a state-of-the-art technique for such investigations.To support the growing demands of planetary science research in China,we have developed a high-efficiency,high-precision method for the integrated analysis of N_(2)and Ar isotopes.This was achieved by enhancing gas extraction and purification systems and integrating them with a static noble gas mass spectrometer.This method enables integrated N_(2)-Ar isotope measurements on submilligram samples,significantly improving sample utilization and reducing the impact of sample heterogeneity on volatile analysis.The system integrates CO_(2)laser heating,a modular two-stage Zr-Al getter pump,and a CuO furnace-based purification process,effectively reducing background levels(N_(2)blank as low as 0.35×10^(−6)cubic centimeters at standard temperature and pressure[ccSTP]).Analytical precision is ensured through calibration with atmospheric air and CO corrections.To validate the reliability of the method,we performed N_(2)-Ar isotope analyses on the Allende carbonaceous chondrite,one of the most extensively studied meteorites internationally.The measured N_(2)concentrations range from 19.2 to 29.8 ppm,withδ15N values between−44.8‰and−33.0‰.Concentrations of 40Ar,36Ar,and 38Ar are(12.5-21.1)×10^(−6)ccSTP/g,(90.9-150.3)×10^(−9)ccSTP/g,and(19.2-30.7)×10^(−9)ccSTP/g,respectively.These values correspond to cosmic-ray exposure ages of 4.5-5.7 Ma,consistent with previous reports.Step-heating experiments further reveal distinct release patterns of N and Ar isotopes,as well as their associations with specific mineral phases in the meteorite.In summary,the combined N_(2)-Ar isotopic system offers significant advantages for tracing volatile sources in extraterrestrial materials and will provide essential analytical support for upcoming Chinese planetary missions,such as Tianwen-2.
