共查询到19条相似文献,搜索用时 62 毫秒
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基体辅助激光解吸电离飞行时间质谱分析糖类的基体 总被引:1,自引:0,他引:1
糖类物质极性高、难挥发、热不稳定,其中多糖还具有相对分子质量分布发散的性质,其质谱表征比较困难。基体辅助激光解吸电离飞行时问质谱(matrix-assisted lazer desorption/ionization time-of-flight mass spectrometry.MALDI-TOFMS)灵敏、快速,对杂质的包容性强、分析的质量范围大,能够对糖类尤其是非衍生化糖进行直接分析。近年来,MALDI-TOFMS的发展已使糖类物质的分析达到一个新的水平。由于基体在MALDI-TOFMS分析中起着至关重要的作用,而研制开发和使用各种有效新基体也一直是MALDI-TOFMS分析的聚焦点,本文综述近10年MALDI-TOFMS分析糖类所用的基体。 相似文献
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葡聚糖的基体辅助激光解吸/电离飞行时间质谱测定 总被引:3,自引:0,他引:3
采用自行设计合成的新基体α-腈基阿魏酸(α-cyano-ferulic acid,简称CFA)并应用激光飞行时间质谱仪的离子偏转功能,对葡聚糖的分子量进行了测定研究。结果表明:与测定糖类物质的常用基体2,5-二羟基苯甲酸(DHB)相比,CFA测定葡聚糖,具有更佳的解吸电离效果,样品易出峰、重现性好、信噪比高;使用仪器的离子偏转器,阻止葡聚糖样品中聚合度较小的离子进入检测器,能显著提高仪器对聚合度较大离子的检测能力,得到质荷比(m/z)更高的质谱峰。 相似文献
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基体辅助激光解吸电解飞行时间质谱用于有参皂甙Rg3的定量分析 总被引:1,自引:0,他引:1
考察了基体辅助激光解吸时间飞行质谱用于人参皂甙Rg3定量分析时内标的选择,加入棉子糖作为内标时,Rg3的定量标准曲线的回归系数R^2=0.938,平均相对误差为28.6%,加入性质相近的芦丁后,Rg3的定量标准曲线的回归系数R^2=0.933,平均相对误差为7.5%,分辨率的提高以及采用Rg3和内标物的质谱峰的相对面积来人表Rg3的浓度可以使定量的重现笥明显改善. 相似文献
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考察了CdTe量子点作为新型无机基质,应用于基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)法分析全氟辛烷磺酸(PFOS),全氟癸烷磺酸(PFDS),全氟己烷磺酸(PFHxS)和全氟庚烷磺酸(PFHpS)4种全氟化合物(PFCs)的效果;同时与传统有机基质α-氰基-4-羟基桂皮酸(CHCA)、1,8-双二甲氨基萘(DMAN)进行比较.实验中,分别将目标分析物与基质溶液滴于样品板上并混合均匀,待自然蒸干溶剂后形成结晶状,采用337 nm波长紫外激光辐照激发,在负离子模式条件下MALDI-TOF-MS分析检测.此外,简要探讨了CdTe量子点颗粒激光辅助解吸离子化的机理.结果表明,CdTe量子点颗粒,具有较强紫外吸收,可直接作为无机基质用于以上4种全氟化合物的MALDI-TOF-MS分析,并且具有提高待测物质谱峰强度等特点. 相似文献
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SUN Ya-dong SUN Shu-chen WANG Zhi YANG Yang ZHANG Jin 《高等学校化学研究》2006,22(3):394-396
Introduction Singlenucleotidepolymorphisms(SNPs)arethe mostabundantDNAmarkersinthehumangenomeoc curringatafrequencyofoneinevery500—1000nu cleotides[1].Avarietyofmethodshavebeenusedfor theanalysisofsinglenucleotidepolymorphisms,inclu dingrestrictionfragme… 相似文献
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Influence Factors on Particle Growth for On-line Aerosol Matrix-assisted Laser Desorption/Ionization Time-of-flight Mass Spectrometry 下载免费PDF全文
An evaporation/condensation flow cell was developed and interfaced with the matrix-assistedlaser desorption/ionization (MALDI) time-of-flight mass spectrometer for on-line bioaerosoldetection and characterization, which allows matrix addition by condensation onto the laboratory-generated bioaerosol particles. The final coated particle exiting from the con-denser is then introduced into the aerodynamic particle sizer spectrometer or home-built aerosol laser time-of-flight mass spectrometer, and its aerodynamic size directly effects on the matrix-to-analyte molar ratio, which is very important for MALDI technique. In order to observe the protonated analyte molecular ion, and then determine the classification of bi-ological aerosols, the matrix-to-analyte molar ratio must be appropriate. Four experimental parameters, including the temperature of the heated reservoir, the initial particle size, its number concentration, and the matrix material, were tested experimentally to analyze their influences on the final particle size. This technique represents an on-line system of detec-tion that has the potential to provide rapid and reliable identification of airborne biological aerosols. 相似文献
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采用碱性新基质2-氨基-5-硝基噻唑对DNA和蛋白质样品进行了基质辅助激光解吸/电离飞行时间质谱分析.结果表明,2-氨基-5-硝基噻唑能有效地解吸电离DNA和蛋白质样品.采用正离子检测模式,分析分子量小于5000的pd(T)10,pd(C)10,pd(A)8,pd(G)10和pd(5′ATCGATCGAT3′)DNA样品时,分辨率均可达到1万以上;与分析DNA样品的常用基质相比,2-氨基-5-硝基噻唑解吸/电离样品分子所需要的激光强度小,易于获得信噪比和分辨率高及重复性好的谱图;分析蛋白质胰岛素、细胞色素C及牛血清白蛋白样品能达到与α-氰基-4-羟基肉桂酸(HCCA)和3,5-二甲氧基-4-羟基肉桂酸(SA)相同的效果.采用负离子检测模式则能以较高的信噪比获得分子量达到7000的DNA的分子离子峰信号.此外,以2-氨基-5-硝基噻唑为基质的基质辅助激光解吸/电离(MALDI)测定还表现出一定的耐盐能力. 相似文献
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Jia-Jun YU Ping LIU Zhen ZENG Ying CHEN Wei GAO Mei LI Chen-Guang WANG Zheng-Xu HUANG Zhen ZHOU Lei LI 《分析化学》2018,46(4):463-470
Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is an important analytical technique for biological macromolecules, such as proteins, peptides and nucleic acid, especially in the field of microbial identification. On the basis of previous study, a linear MALDI-TOF MS was been designed and assembled for biological applications. The instrument comprised a vacuum system, a vacuum fast sample introduction system, an optical system, a time-of-flight mass analyzer, an ion source, a data acquisition system and an electronic control system. The ion source adopted two-stage source acceleration, delayed extraction and dynamic pulse focusing technique. The time-of-flight distance of field-free drift region was about 1 m. The optical system adopted a solid-state laser with adjustable frequency of 1–2000 Hz and spots of 20–100 μm. The angle of incidence laser was controlled at 5°. A series of experiments were carried out to further evaluate the instrument performances. It could not only analyze the samples more than 199 kDa, but also achieve isotope resolution at 1000–3000 Da and up to 900 (FWHM) at 5000–17000 Da. The minimum detectable concentration of gramicidin was 10 amol μL?1, absolute sensitivity reached up to 2.56 amol. Independent detection of saliva samples from different targets showed that the instrument had higher producibility. We identified Escherichia coli and Shigella spp., which are two common bacteria but difficult to be differentiated by mass spectrometry, showing its potential identification for clinical microorganism. In summary, this instrument can play a role on clinical examination in the near future. 相似文献
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TSAO Rong 《高等学校化学研究》2010,26(1):11-16
A simple method was developed for rapid and direct profiling of alkaloids in medical herbs via matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS). The dry herbs were first ground to powder and passed through a stainless steel sieve, mixed with the matrix solution to form a homogeneous suspension, which was then directly applied to MALDI analysis. Several matrices were investigated and 2,5-dihydroxybenzoic acid(DHB) was chosen as the optimized one, and the particle wit... 相似文献
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基体辅助激光解吸—电离飞行时间质谱法分析衍生化的寡链糖 总被引:1,自引:0,他引:1
以2,5-二羟基苯甲酸(DHB)+间硝基苄醇(NBA)混合基体辅助激光解吸电离飞行时间质谱法(MALDI)分析甲壳素降解并衍生化的寡链糖,获得了满意的结果。对比其它基体,如:芥子酸(SA)、α-氰基-4-羟基肉桂酸等(α_CHCA),2,5_DHB+NBA混合基体解吸电离效果最好:信号强、信噪比高。甲壳素降解产物的质谱分析至今未见报道。 相似文献
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基质辅助激光解吸电离质谱表征新型环状聚芳酯预聚体 总被引:3,自引:1,他引:3
应用基质辅助激光解吸电离质谱技术对新型环状聚芳酯预聚体进行了表征,从而确定了该环素聚合物不同聚合度(n=1,2……8)的存在,获得了满意的结果。实验证明本方法是测定环状聚合物不同聚合度快速、有效、准确的方法。 相似文献