The chemical ionization mass spectra of ten different glucosinolates isolated from rape seed have been studied. More intense diagnostic ions were identified than in the electron impact mass spectra. The method is suit...The chemical ionization mass spectra of ten different glucosinolates isolated from rape seed have been studied. More intense diagnostic ions were identified than in the electron impact mass spectra. The method is suitable for the structure analysis of mixture of glucosinolates.展开更多
The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion ...The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion mode. Polyethylene glycol (PEG) was used as the internal reference. All results were obtained under the resolution of about 5000 FWHM (full width at the half maximum). Solvent effects were studied and the satisfied results were obtained in acetonitrile. Compared with the theoretical values, all absolute errors were less than 1.0 mmu. The effects of nozzle potential, push pulse potential, pull pulse potential, pull bias potential and acquisition rate on exact mass determination were also discussed. APCI/TOF MS is proven to be a very sensitive analytical technique and an alternative ionization mode in analyzing thermally labile compounds with relatively weak polarity, such as α allenic alcohol.展开更多
Although the eminent threat of a terrorist group detonating an improvised nuclear device (IND) in an urban environment is low, it is crucial that countries develop modern nuclear forensic capabilities to expedite resp...Although the eminent threat of a terrorist group detonating an improvised nuclear device (IND) in an urban environment is low, it is crucial that countries develop modern nuclear forensic capabilities to expedite response in a post-detonation scenario. In particular, new instruments need to be created to shorten dissolution time, expedite chemical separation, and improve forensic analysis of the nuclear melt glass that is created during the detonation of the device. To expedite this process, an instrument was designed to thermally couple a gas chromatograph (GC) to a time-of-flight inductively coupled plasma time-of-flight mass spectrometer (ICPTOFMS) In order to couple these two instruments, another instrument was designed to provide an isothermal atmosphere between the GC and TOFICPMS to expedite rapid gas separations processes. By using gas separations instead of the current wet chemistry processes, the required separation and analysis time of the melt glass significantly decreases. The new instrument would also provide a more detailed analysis of the elemental and isotopic composition of the melt glass. By completing these tasks simultaneously, this significantly decreases the required time to conduct these separations and improves the elemental and isotopic analysis.展开更多
使用超高效液相色谱-串联质谱法,建立饼干中大麻酚、大麻二酚和四氢大麻酚的测定方法。样品经乙腈醋酸(99+1)提取,加入醋酸体系盐包超声离心后,再加入吸附剂离心。采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过C18色谱柱分离,大气压...使用超高效液相色谱-串联质谱法,建立饼干中大麻酚、大麻二酚和四氢大麻酚的测定方法。样品经乙腈醋酸(99+1)提取,加入醋酸体系盐包超声离心后,再加入吸附剂离心。采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过C18色谱柱分离,大气压化学电子源(atmospheric pressure chemical ionization,APCI)正离子多反应模式监测。通过考察不同种类提取溶剂、超声时间、萃取盐包组成、吸附剂组成的目标化合物回收率,确定最优前处理方式。结果表明:大麻酚、大麻二酚、四氢大麻酚在2~100 ng/mL时呈现良好线性关系,相关系数(R2)均大于0.999,方法检出限0.01 mg/kg,定量限0.02 mg/kg。低、中、高3个浓度加标回收试验,大麻酚回收率为80.3%~91.1%,相对标准偏差(relative standard deviation,RSD)为2.4%~6.5%,大麻二酚回收率为78.4%~88.5%,RSD为2.9%~7.5%,四氢大麻酚回收率为81.5%~91.3%,RSD为2.6%~6.8%。该方法适用于饼干中大麻酚、大麻二酚和四氢大麻酚的检测。展开更多
为快速评价郫县豆瓣酱发酵过程中香气物质的差异性,利用流过式介质电离质谱(soft ionization by chemical reaction in transfer-mass spectrometry,SICRIT-MS)技术结合多元统计方法,对不同发酵时期的郫县豆瓣酱的香气物质进行了代谢组...为快速评价郫县豆瓣酱发酵过程中香气物质的差异性,利用流过式介质电离质谱(soft ionization by chemical reaction in transfer-mass spectrometry,SICRIT-MS)技术结合多元统计方法,对不同发酵时期的郫县豆瓣酱的香气物质进行了代谢组学研究。结果显示,SICRIT-MS完成单次检测仅需要1~3 s。此外,在质谱正离子模式下筛选了18个差异成分,负离子模式下11个差异成分。这些成分可以作为潜在的鉴别不同发酵时期豆瓣酱样品的特征标记成分。SICRIT-MS结合代谢组学技术为实现郫县豆瓣酱快速分级提供理论和技术支撑。展开更多
20-Hydroxyecdysone(20E)derived from plants has a wide range of physiological and pharmacological ef ects on animals and humans,and rapid and sensitive methods for screening of the endogenous 20E in plants are thus req...20-Hydroxyecdysone(20E)derived from plants has a wide range of physiological and pharmacological ef ects on animals and humans,and rapid and sensitive methods for screening of the endogenous 20E in plants are thus required.Herein,a matrixassisted laser desorption/ionization time-of-f ight tandem mass spectrometry(MALDI-TOF/TOF MS)method is described for rapid and sensitive determination of endogenous 20E in plants.It is based on the use of the(3-(acridin-9-ylamino)phenyl)boronic acid(AYPBA)as the mass tag to assist the MS and tandem MS(MS^(n))analysis of 20E on MALDI-TOF/TOF MS.Good linearity was obtained with a determination coef cient(R^(2))larger than 0.99 in the range of 0.025–2.5μΜ.The limit of detection(LOD)was 2.4 fmol.Acceptable precision and accuracy were gained by intra-and inter-day analysis with relative standard deviations less than 19.5%and relative recoveries ranging from 85.7 to 105.2%.In addition,the AYPBA labeled 20E produced abundant characteristic fragment ions under the high energy collision-induced dissociation,which facilitated the identif cation of 20E by MS^(2)analysis on MALDI-TOF/TOF MS.Using the method,we enabled the identif cation and quantif cation of endogenous 20E in four herbs including Cyanotis arachoidea,Achyranthes bidentata,Spinacia oleracea and Chenopodium quinoa willd.,demonstrating the feasibility of the proposed method for screening of the endogenous 20E in plants.展开更多
Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively...Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively inert, causing no irritation and allergies. Poly(ethylene oxide)(PEO) hydrogels were prepared using pentaerythritol tetra-acrylate(PETRA) as UV crosslinking agent. A simple, accurate, and robust quantitation method was developed based on gas chromatographic techniques(GC), which is suitable for routine analysis of residual PETRA monomers in these hydrogels. Unreacted PETRA was initially identified using gas chromatography–mass spectrometry(GC–MS). The quantitation of analyte was performed and validated using gas chromatography equipped with a flame ionization detector(GC–FID). A linear relationship was obtained over the range of 0.0002%–0.0450%(m/m) with a correlation coefficient(r2)greater than 0.99. The recovery( 4 90%), intra-day precision(%RSD o 0.67), inter-day precision(%RSD o2.5%), and robustness(%RSD o1.62%) of the method were within the acceptable values. The limit of detection(LOD) and limit of quantitation(LOQ) were 0.0001%(m/m) and 0.0002%(m/m), respectively.This assay provides a simple and quick way of screening for residual acrylate monomer in hydrogels.展开更多
文摘The chemical ionization mass spectra of ten different glucosinolates isolated from rape seed have been studied. More intense diagnostic ions were identified than in the electron impact mass spectra. The method is suitable for the structure analysis of mixture of glucosinolates.
基金theNationalNaturalScienceFoundationofChina (No .2 0 175 0 3 4)
文摘The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion mode. Polyethylene glycol (PEG) was used as the internal reference. All results were obtained under the resolution of about 5000 FWHM (full width at the half maximum). Solvent effects were studied and the satisfied results were obtained in acetonitrile. Compared with the theoretical values, all absolute errors were less than 1.0 mmu. The effects of nozzle potential, push pulse potential, pull pulse potential, pull bias potential and acquisition rate on exact mass determination were also discussed. APCI/TOF MS is proven to be a very sensitive analytical technique and an alternative ionization mode in analyzing thermally labile compounds with relatively weak polarity, such as α allenic alcohol.
文摘Although the eminent threat of a terrorist group detonating an improvised nuclear device (IND) in an urban environment is low, it is crucial that countries develop modern nuclear forensic capabilities to expedite response in a post-detonation scenario. In particular, new instruments need to be created to shorten dissolution time, expedite chemical separation, and improve forensic analysis of the nuclear melt glass that is created during the detonation of the device. To expedite this process, an instrument was designed to thermally couple a gas chromatograph (GC) to a time-of-flight inductively coupled plasma time-of-flight mass spectrometer (ICPTOFMS) In order to couple these two instruments, another instrument was designed to provide an isothermal atmosphere between the GC and TOFICPMS to expedite rapid gas separations processes. By using gas separations instead of the current wet chemistry processes, the required separation and analysis time of the melt glass significantly decreases. The new instrument would also provide a more detailed analysis of the elemental and isotopic composition of the melt glass. By completing these tasks simultaneously, this significantly decreases the required time to conduct these separations and improves the elemental and isotopic analysis.
文摘使用超高效液相色谱-串联质谱法,建立饼干中大麻酚、大麻二酚和四氢大麻酚的测定方法。样品经乙腈醋酸(99+1)提取,加入醋酸体系盐包超声离心后,再加入吸附剂离心。采用0.1%甲酸水溶液和甲醇为流动相,梯度洗脱,通过C18色谱柱分离,大气压化学电子源(atmospheric pressure chemical ionization,APCI)正离子多反应模式监测。通过考察不同种类提取溶剂、超声时间、萃取盐包组成、吸附剂组成的目标化合物回收率,确定最优前处理方式。结果表明:大麻酚、大麻二酚、四氢大麻酚在2~100 ng/mL时呈现良好线性关系,相关系数(R2)均大于0.999,方法检出限0.01 mg/kg,定量限0.02 mg/kg。低、中、高3个浓度加标回收试验,大麻酚回收率为80.3%~91.1%,相对标准偏差(relative standard deviation,RSD)为2.4%~6.5%,大麻二酚回收率为78.4%~88.5%,RSD为2.9%~7.5%,四氢大麻酚回收率为81.5%~91.3%,RSD为2.6%~6.8%。该方法适用于饼干中大麻酚、大麻二酚和四氢大麻酚的检测。
文摘为快速评价郫县豆瓣酱发酵过程中香气物质的差异性,利用流过式介质电离质谱(soft ionization by chemical reaction in transfer-mass spectrometry,SICRIT-MS)技术结合多元统计方法,对不同发酵时期的郫县豆瓣酱的香气物质进行了代谢组学研究。结果显示,SICRIT-MS完成单次检测仅需要1~3 s。此外,在质谱正离子模式下筛选了18个差异成分,负离子模式下11个差异成分。这些成分可以作为潜在的鉴别不同发酵时期豆瓣酱样品的特征标记成分。SICRIT-MS结合代谢组学技术为实现郫县豆瓣酱快速分级提供理论和技术支撑。
基金supported by the National Key R&D Program of China(2017YFC0906800)the National Natural Science Foundation of China(21635006,31670373 and 21721005)
文摘20-Hydroxyecdysone(20E)derived from plants has a wide range of physiological and pharmacological ef ects on animals and humans,and rapid and sensitive methods for screening of the endogenous 20E in plants are thus required.Herein,a matrixassisted laser desorption/ionization time-of-f ight tandem mass spectrometry(MALDI-TOF/TOF MS)method is described for rapid and sensitive determination of endogenous 20E in plants.It is based on the use of the(3-(acridin-9-ylamino)phenyl)boronic acid(AYPBA)as the mass tag to assist the MS and tandem MS(MS^(n))analysis of 20E on MALDI-TOF/TOF MS.Good linearity was obtained with a determination coef cient(R^(2))larger than 0.99 in the range of 0.025–2.5μΜ.The limit of detection(LOD)was 2.4 fmol.Acceptable precision and accuracy were gained by intra-and inter-day analysis with relative standard deviations less than 19.5%and relative recoveries ranging from 85.7 to 105.2%.In addition,the AYPBA labeled 20E produced abundant characteristic fragment ions under the high energy collision-induced dissociation,which facilitated the identif cation of 20E by MS^(2)analysis on MALDI-TOF/TOF MS.Using the method,we enabled the identif cation and quantif cation of endogenous 20E in four herbs including Cyanotis arachoidea,Achyranthes bidentata,Spinacia oleracea and Chenopodium quinoa willd.,demonstrating the feasibility of the proposed method for screening of the endogenous 20E in plants.
文摘Acrylates have been widely used in the synthesis of pharmaceutical polymers. The quantitation of residual acrylate monomers is vital as they are strong irritants and allergens, but after polymerization, are relatively inert, causing no irritation and allergies. Poly(ethylene oxide)(PEO) hydrogels were prepared using pentaerythritol tetra-acrylate(PETRA) as UV crosslinking agent. A simple, accurate, and robust quantitation method was developed based on gas chromatographic techniques(GC), which is suitable for routine analysis of residual PETRA monomers in these hydrogels. Unreacted PETRA was initially identified using gas chromatography–mass spectrometry(GC–MS). The quantitation of analyte was performed and validated using gas chromatography equipped with a flame ionization detector(GC–FID). A linear relationship was obtained over the range of 0.0002%–0.0450%(m/m) with a correlation coefficient(r2)greater than 0.99. The recovery( 4 90%), intra-day precision(%RSD o 0.67), inter-day precision(%RSD o2.5%), and robustness(%RSD o1.62%) of the method were within the acceptable values. The limit of detection(LOD) and limit of quantitation(LOQ) were 0.0001%(m/m) and 0.0002%(m/m), respectively.This assay provides a simple and quick way of screening for residual acrylate monomer in hydrogels.
