Fast and unequivocal methods of questioned document analysis are essential in forensic science. Here, a desorption/ionization technique, EASI-MS, was assessed for its ability to investigate questioned driver’s licens...Fast and unequivocal methods of questioned document analysis are essential in forensic science. Here, a desorption/ionization technique, EASI-MS, was assessed for its ability to investigate questioned driver’s licenses (DL). Two suspects DL, displaying the same personal data in the proper fields (name and ID numbers), but with different individual photos, showing similar impressions on microscopic analysis, and authentic standards documents specimens were used as test cases. Profiles from authentic DL surface were dominated by a set of few minor ions, mainly from the plasticizers bis(2-ethylhexyl)phthalate and dibutylphthalate. The seized suspect counterfeit DL on points from personal data and photo were, however, dominated by abundant diagnostic ions of m/z 463, 507, 551, 595, 639, 683, which confirmed counterfeiting. Surfynol<sup>®</sup> and Nonoxynol-9<sup>®</sup>, which are common constituents of inkjet printing, were detected in the counterfeiting areas by high-accuracy EASI(+)-FT-ICR MS. The EASI-MS technique is shown therefore to offer an attractive tool for forensic investigation of questioned documents.展开更多
Fast detection of trace lysozyme,one of the most important food allergens in white wine samples,was achieved by extractive electrospray ionization mass spectrometry without sample pretreatment in this study.The multip...Fast detection of trace lysozyme,one of the most important food allergens in white wine samples,was achieved by extractive electrospray ionization mass spectrometry without sample pretreatment in this study.The multiply-charged ions of m/z1587 were chosen for the quantitative detection of lysozyme in white wine,showing linear dynamic signal responses in a range of 5―75μg/mL with a linearity coefficient of 0.999 and an acceptable relative standard deviation（RSD） of 8.0%―15.0% for directly measuring lysozyme in the complex food samples.The limit of detection for lysozyme in white wine sample was calculated to be 5 μg/mL,which was lower than the amounts that can provoke allergic reactions（oral test with 3 mg or labial test with 1 mg/mL）.A single sample analysis was completed within 1 min.The data demonstrate that extractive electrospray ionization mass spectrometry is a useful tool for fast screening lysozyme in the complex matrix,showing promising application in the rapid detection of food allergen.展开更多
In this study,an ambient mass spectrometry(AMS)based method was developed for rapid detection of organophosphorus pesticides in strawberry.This method combines an electric arc and a microsyringe tip to realize tip-ass...In this study,an ambient mass spectrometry(AMS)based method was developed for rapid detection of organophosphorus pesticides in strawberry.This method combines an electric arc and a microsyringe tip to realize tip-assisted ambient electric arc ionization(TAAEAI).A high-voltage electric arc can be applied to the microsyringe tip to generate an electric field,which results in corona discharge at the microsyringe tip.The juiced strawberry sample loaded on the tip could be directly ionized with TAAEAI and then analyzed by a mass spectrometer.TAAEAI-MS was successfully applied to analyze 6 organophosphorus pesticides in three strawberry samples.Malathion and profenofos were detected from the investigated strawberry samples.This method could quantitatively determine the contents of organophosphorus pesticides in strawberry with high reproducibility,high precision,and high sensitivity.Sample matrices did not interfere with the pesticide analysis.The recoveries of organophosphorus pesticides spiked in strawberry samples varied between 82.6%and 116%with relative standard deviations(RSDs)less than 9.2%.The limits of detection(LODs)varied between 0.0124µg/g and 0.0245µg/g,while the limits of quantification(LOQs)varied between 0.0413µg/g and 0.0817µg/g.The coefficients of determination(R2)of the method were determined to be>0.995.The method established here may have potential application in the detection of organophosphorus pesticides in vegetables and fruits.展开更多
Salinity tolerance of ambient electric arc ionization(AEAI)was evaluated by comparing electrospray ionization for various samples at NaCl concentrations from 0 to 1000 mmol/L.AEAI-mass spectrometry(AEAI-MS)exhibited a...Salinity tolerance of ambient electric arc ionization(AEAI)was evaluated by comparing electrospray ionization for various samples at NaCl concentrations from 0 to 1000 mmol/L.AEAI-mass spectrometry(AEAI-MS)exhibited an excellent signal intensity even at NaCl concentrations of 1000 mmol/L,while the ESI-MS had no signal because high salinity has a strong inhibitory effect on analytes.The sodium adduct was verified using LiCl instead of NaCl.AEAI-MS successfully quantified saline samples with an excellent quantitative ability(R^(2)≥0.998).We also achieved some analytical samples in the buffer solution at a very high concentration and even in a saturated salt solution.Overall,AEAI-MS has protonated ions for most target analytes.In addition,the relationship between auxiliary temperature and the distance from the sample to the arc was investigated,and the results indicated that thermal desorption plays an important role in AEAI source.展开更多
Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHM...Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS)for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future.展开更多
敞开式离子化质谱(ambient ionization mass spectrometry,AIMS)是近年来兴起的一种无需(或稍许)样品前处理步骤,在敞开的大气环境下实现离子化的质谱分析技术。近年来,各种AIMS技术的研制与应用成为质谱领域备受关注的焦点之一。本工...敞开式离子化质谱(ambient ionization mass spectrometry,AIMS)是近年来兴起的一种无需(或稍许)样品前处理步骤,在敞开的大气环境下实现离子化的质谱分析技术。近年来,各种AIMS技术的研制与应用成为质谱领域备受关注的焦点之一。本工作综述了AIMS技术在中草药研究中的应用,对典型的分析策略进行了讨论,阐述了AIMS技术的基本原理、特点和分类,并展望了该技术在中医药研究领域的发展趋势和可能影响。展开更多
近年来,无需复杂样品前处理、且在开放环境下实现离子化的常压敞开式离子化质谱技术(Ambientionization mass spectrometry,AI-MS)的研制与应用成为质谱学领域的前沿及备受关注的研究方向。该文综述了AI离子源的基本原理、特征与应用进...近年来,无需复杂样品前处理、且在开放环境下实现离子化的常压敞开式离子化质谱技术(Ambientionization mass spectrometry,AI-MS)的研制与应用成为质谱学领域的前沿及备受关注的研究方向。该文综述了AI离子源的基本原理、特征与应用进展,并结合笔者研制的空气动力辅助离子化(Air flow assisted ioniza-tion,AFAI)技术,介绍了气流辅助常压敞开式离子化技术的基本特点及其应用。展望了常压敞开式离子化技术的发展趋势。展开更多
文摘Fast and unequivocal methods of questioned document analysis are essential in forensic science. Here, a desorption/ionization technique, EASI-MS, was assessed for its ability to investigate questioned driver’s licenses (DL). Two suspects DL, displaying the same personal data in the proper fields (name and ID numbers), but with different individual photos, showing similar impressions on microscopic analysis, and authentic standards documents specimens were used as test cases. Profiles from authentic DL surface were dominated by a set of few minor ions, mainly from the plasticizers bis(2-ethylhexyl)phthalate and dibutylphthalate. The seized suspect counterfeit DL on points from personal data and photo were, however, dominated by abundant diagnostic ions of m/z 463, 507, 551, 595, 639, 683, which confirmed counterfeiting. Surfynol<sup>®</sup> and Nonoxynol-9<sup>®</sup>, which are common constituents of inkjet printing, were detected in the counterfeiting areas by high-accuracy EASI(+)-FT-ICR MS. The EASI-MS technique is shown therefore to offer an attractive tool for forensic investigation of questioned documents.
基金Supported by the Project of National Institute of Metrology of China(No.21-YS1046)
文摘Fast detection of trace lysozyme,one of the most important food allergens in white wine samples,was achieved by extractive electrospray ionization mass spectrometry without sample pretreatment in this study.The multiply-charged ions of m/z1587 were chosen for the quantitative detection of lysozyme in white wine,showing linear dynamic signal responses in a range of 5―75μg/mL with a linearity coefficient of 0.999 and an acceptable relative standard deviation（RSD） of 8.0%―15.0% for directly measuring lysozyme in the complex food samples.The limit of detection for lysozyme in white wine sample was calculated to be 5 μg/mL,which was lower than the amounts that can provoke allergic reactions（oral test with 3 mg or labial test with 1 mg/mL）.A single sample analysis was completed within 1 min.The data demonstrate that extractive electrospray ionization mass spectrometry is a useful tool for fast screening lysozyme in the complex matrix,showing promising application in the rapid detection of food allergen.
基金supported by National Natural Science Foundation of China(No.21927810)the Project of Experimental Technology and Management(No.SYJS2020010)the laboratorybased open project in Sichuan Normal University(No.KFSY2020004).
文摘In this study,an ambient mass spectrometry(AMS)based method was developed for rapid detection of organophosphorus pesticides in strawberry.This method combines an electric arc and a microsyringe tip to realize tip-assisted ambient electric arc ionization(TAAEAI).A high-voltage electric arc can be applied to the microsyringe tip to generate an electric field,which results in corona discharge at the microsyringe tip.The juiced strawberry sample loaded on the tip could be directly ionized with TAAEAI and then analyzed by a mass spectrometer.TAAEAI-MS was successfully applied to analyze 6 organophosphorus pesticides in three strawberry samples.Malathion and profenofos were detected from the investigated strawberry samples.This method could quantitatively determine the contents of organophosphorus pesticides in strawberry with high reproducibility,high precision,and high sensitivity.Sample matrices did not interfere with the pesticide analysis.The recoveries of organophosphorus pesticides spiked in strawberry samples varied between 82.6%and 116%with relative standard deviations(RSDs)less than 9.2%.The limits of detection(LODs)varied between 0.0124µg/g and 0.0245µg/g,while the limits of quantification(LOQs)varied between 0.0413µg/g and 0.0817µg/g.The coefficients of determination(R2)of the method were determined to be>0.995.The method established here may have potential application in the detection of organophosphorus pesticides in vegetables and fruits.
基金supported by the China State Key Research Program(No.2016YFF0200503)National Natural Science Founda-tion of China(No.21927810)Sichuan Normal University(Nos.SYJS2020010 and KFSY2020004).
文摘Salinity tolerance of ambient electric arc ionization(AEAI)was evaluated by comparing electrospray ionization for various samples at NaCl concentrations from 0 to 1000 mmol/L.AEAI-mass spectrometry(AEAI-MS)exhibited an excellent signal intensity even at NaCl concentrations of 1000 mmol/L,while the ESI-MS had no signal because high salinity has a strong inhibitory effect on analytes.The sodium adduct was verified using LiCl instead of NaCl.AEAI-MS successfully quantified saline samples with an excellent quantitative ability(R^(2)≥0.998).We also achieved some analytical samples in the buffer solution at a very high concentration and even in a saturated salt solution.Overall,AEAI-MS has protonated ions for most target analytes.In addition,the relationship between auxiliary temperature and the distance from the sample to the arc was investigated,and the results indicated that thermal desorption plays an important role in AEAI source.
基金supported by the National Natural Science Foundation of China(No.82072247)to MZthe Young Scholar Project of Beijing University of Chinese Medicine(Nos.2019-JYBJS-017 and 2021-JYB-XJSJJ001)to SJ and MZ。
文摘Chinese herbal medicines(CHMs)play an increasingly important role in the field of medicine and affects public health in the world.Although more and more strict has been employed to ensure the quality and safety of CHMs,pesticide residues in CHMs remain a serious issue and are the bottleneck for the global development of CHMs.In this work,we applied molecularly imprinted membrane electrospray mass spectrometry(MIM-ESI MS)for rapid detecting 4 classes of pesticide residues in CHMs,including organophosphorus(OPP),carbamates,pyrethroids and neonicotinoids in CHMs.Compared with our previous ambient ionization method MESI,MIM-ESI is capable of achieving a~50-fold increase in the detection limit of conventional analytical methods owing to the specificity recognition and unique enrichment of MIM.The optimal experimental conditions were determined,and the method was further validated for its sensitivity and specificity.Our data showed that MIM-ESI MS is applicable for the direct quantitation of pesticide residues in CHMs.This detection technology may help to ensure the quality of CHMs in the future.
文摘敞开式离子化质谱(ambient ionization mass spectrometry,AIMS)是近年来兴起的一种无需(或稍许)样品前处理步骤,在敞开的大气环境下实现离子化的质谱分析技术。近年来,各种AIMS技术的研制与应用成为质谱领域备受关注的焦点之一。本工作综述了AIMS技术在中草药研究中的应用,对典型的分析策略进行了讨论,阐述了AIMS技术的基本原理、特点和分类,并展望了该技术在中医药研究领域的发展趋势和可能影响。
