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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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研究了基体溶液的pH值对基体辅助激光解吸电离(MALDI)的影响,测定了从强酸至强碱不同pH值的α-氰基,4-羟基肉桂酸水溶液的紫外吸收谱,并分别用作基体测定细胞色素C的相对分子质量。结果显示除按常规配制的基体溶液(pH=2.5)在激光波长355nm处有强紫外吸收外,其他pH=1.0、pH=8.0、pH=10.0的溶液皆没有吸收,而相对分子质量测量结果是pH=1.0和pH=2.5两种溶液可得到质量 相似文献
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基体辅助激光解吸/电离质谱(MALDIMS)法自80年代末由Karas,Hilenkamp报道以来,已获得极大的发展.近几年来,其应用范围迅速扩大,各种生物大分子如蛋白质,核酸(DNA),多糖等都已能用MALDIMS法进行分子量测定.1993年,... 相似文献
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选用包括纳米粒子在内的多种基质化合物,构成了多种不同组成的液相基质.以多肽、蛋白、大环寡糖和有机小分子等数种类型化合物为样品,系统地考察了不同液相基质在基质辅助激光解吸电离飞行时间质谱(MALDI-TOF)分析中的应用情况,探讨了与固体制样方法的异同点.实验结果表明,有些液相基质对多类化合物具有较好的通用性,而有些液相基质对某些特定类型化合物的分析特别有效. 相似文献
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《Analytical letters》2012,45(16):2553-2565
Online matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is reported with in situ matrix/analyte aerosol mixing. The analyte and matrix were dissolved in separate solvents and pneumatically atomized into particles. Continuous flows of analyte particles and matrix droplets in nitrogen were mixed in a tee. The resulting particles were sampled using a nozzle, focused into a beam with an aerodynamic lens system, and vertically deposited continuously on a movable target. The matrix/analyte mixture was desorbed/ionized using a 266 nanometers pulsed laser at an incident angle of 45°. The nascent ions were analyzed using reflectron TOF MS. The performance of online MALDI-TOF MS was evaluated by the analysis of palmityl palmitate with the lithium salt of 2, 4-dihydroxybenzoic acid as the matrix. Strong and stable MALDI signals of palmityl palmitate were obtained. The matrix solvent mixture and the analyte concentration were optimized and the results demonstrate the development of an alternative for online MALDI analysis. 相似文献
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金黄色葡萄球菌及其甲氧苯青霉素耐药性的MALDI-TOF MS鉴定 总被引:7,自引:1,他引:7
用MALDI-TOS MS细菌指纹图谱鉴定细菌,建立区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的MALDI-TOF MS分析方法,检测了76株从临床标本中分离得到的金黄色葡萄球菌,用软件进行聚类分析,以nuc(耐热核酸酶)基因和mecA(耐药)基因聚合酶链反应(PCR)检测结果为参照,74%的菌株经MALDI-TOF MS给出了正确的鉴定结果;金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株的质谱图有很大差别,各自有其特征峰;经过软件聚类分析,76株实验菌株划敏感群和耐药群;与PCR检测结果对照,有7株菌PCR检测mecA基因为阴性,而经MALDI-TOF MS鉴定为耐药株,表型鉴定表明其中有5株为敏感株;利用细菌指纹图谱和数据库检索对大多数菌株实现了正确鉴定;MALDI-TOF MS分辨率高,甚至可以区分株间的差异,实现了区分金黄色葡萄球菌甲氧苯青霉素耐药株和敏感株;结果表明MALDI-TOF MS提供了一个很有前景的鉴定细菌的快速方法。 相似文献
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本文介绍了一种用基本辅助激光解吸电离质谱法快速测定蛋清中溶菌酶相对分子质量的方法。与传统的蛋白质相对分子质量测定相比,MALDI/MS法具有灵敏度高、精度高、易操作和分析时间短的优点,包括样品处理在内,一次分析不超过30min。 相似文献
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Kermit K. Murray David H. Russell 《Journal of the American Society for Mass Spectrometry》1994,5(1):1-9
A new method of liquid sample introduction for a time-of-flight mass spectrometer (TOF-MS) has been developed by applying the method of matrix-assisted laser desorption ionization to aerosols. Analyte biomolecules are dissolved in a methanol solvent along with a UVabsorbing matrix and formed into an aerosol with a pneumatic nebulizer. The aerosol particles are dried in a heated skimmer tube before ionization by pulsed 355-nm UV laser radiation. Mass analysis is achieved in a linear TOF-MS. Results for the ionization of bovine insulin (5733.5 Mw) are reported. 相似文献
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聚芳醚砜环状低聚物的基质辅助激光解吸电离质谱分析 总被引:3,自引:2,他引:3
采用基质辅助激光解吸电离飞行时间质谱技术分别对两种合成的聚芳醚砜环状低聚物进行了分析研究,并讨论了低聚物中不同聚合度离子组份的分布规律。 相似文献
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代莉莉 《分析测试技术与仪器》2022,28(4):375-383
基质辅助激光解析电离飞行时间质谱(MALDI-TOF-MS)在合成聚合物的表征手段中具有不可替代的优点,可以提供聚合物的质量分布、嵌段长度、端基等信息.但由于合成聚合物的离子化效率通常不佳,因此样品制备是分析成功的关键.从基质、基质添加剂以及混样方式3个方面综述了MALDI-TOF质谱分析合成聚合物样品制备的研究进展. 相似文献
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Chieh-Hsin Lin Hung Su Chung-Chieh Hung Hsien-Yuan Lane Jentaie Shiea 《Molecules (Basel, Switzerland)》2021,26(15)
Matrix-assisted laser desorption ionization/time-of-flight (MALDI-TOF) mass spectrometry is a sensitive analytical tool for characterizing various biomolecules in biofluids. In this study, MALDI-TOF was used to characterize potential plasma biomarkers for distinguishing patients with major depressive disorder (MDD) from patients with schizophrenia and healthy controls. To avoid interference from albumin—the predominant protein in plasma—the plasma samples were pretreated using acid hydrolysis. The results obtained by MALDI-TOF were also validated by electrospray ionization-quadrupole time-of-flight (ESI-QTOF) mass spectrometry. The analytical results were further treated with principal component analysis (PCA), hierarchical clustering analysis (HCA), and receiver operating characteristic (ROC) curve analysis. The statistical analyses showed that MDD patients could be distinguished from schizophrenia patients and healthy controls by the lack of apolipoprotein C1 (Apo C1), which, in fact, was detected in healthy controls and schizophrenia patients. This protein is suggested to be a potential plasma biomarker for distinguishing MDD patients from healthy controls and schizophrenia patients. Since sample preparation for MALDI-TOF is very simple, high-throughput plasma apolipoprotein analysis for clinical purposes is feasible. 相似文献