甘油快原子轰击质谱的量子化学研究

用标准MNDO方法优化了甘油快原子轰击正离子谱中的主要离子构型,计算了生成热、质子化能以及亚稳断裂的活化势垒,研究了质子化甘油二步脱水反应的机理,并指出脱水产物C_3H_5O~+离子存在2种不同的构型。     

α—氨基酸的快原子轰击质谱

本文研究了１８种α－氨基酸的快原子轰击质谱，发现添加三氟乙酸溶液能显著提高灵敏度，改善谱图。特征碎片主要有中性丢失ＣＯ２Ｈ２，Ｈ２Ｏ，ＮＨ３的离子以及Ｒ＾＋离子。侧链的性质决定了碎片的产生和离子的强弱。     

含酯糖链皂甙的负离子快原子轰击质谱分析

本实验用负离子快原子轰击(FAB)法测定了8个含酯糖链的双糖链皂甙样品,给出了明显的脱质子分子离子峰,由碎片离子峰可推测糖基的连接顺序;不仅对难挥发、热不稳定和极性大的样品可直接进样分析,而且对在酯糖链皂甙中出现以酯裂解为基峰的碎片,还可初步确定糖链在甙元上的连接位置。     

金属盐在某些底物中的快原子轰击质谱

本文通过研究一系列盐类化合物在底物三乙醇胺和甘油醚中的快原子轰击质谱,总结出它们的加合阳离子系列,并从快原子轰击质谱的离化机理和亚稳跃迁结果探讨了这些离子的来源。     

快原子轰击质谱的非线性拟合法定量分析取代基海因

采用快原子轰击质谱法，在有底物甘油的条件下，测定f-5，5-二甲基海因，5-甲基-5-乙基海因的准分子离子峰[M＋H]^＋的质量色谱图，通过对其曲线拟合，发现它们的强度随采集时间呈指数衰减规律，并且，二者初始峰强的比值与仅与二者的浓度有关。当选定一个作为内标，则可对另一个定量分析。实验选择5-甲基-5-乙基海因作为内标，对5，5-二甲基海因定量分析。测得标准曲线方程为y=-0．0204＋0．154x（R=0．9921），线性范围在1～25μg之间，RSD为3．0％。     

冠醚稀土络合物的快原子轰击质谱

本文报道十余个冠醚稀土络合物的快原子轰击质谱(FABMS)。通过分析FABMS的特征及亚稳离子分解讨论了溶液中的反应和络合性质。     

快原子轰击质谱的非线性拟合法定量分析取代基海因

采用快原子轰击质谱法,在有底物甘油的条件下,测定了5,5-二甲基海因,5-甲基-5-乙基海因的准分子离子峰[M+H]+的质量色谱图,通过对其曲线拟合,发现它们的强度随采集时间呈指数衰减规律,并且,二者初始峰强的比值与仅与二者的浓度有关.当选定一个作为内标,则可对另一个定量分析.实验选择5-甲基-5-乙基海因作为内标,对5,5-二甲基海因定量分析.测得标准曲线方程为y=-0.0204+0.154x(R=0.9921),线性范围在1～25 μg之间,RSD为3.0% .     

多肽的快原子轰击质谱／质谱研究

通过快原子轰击质谱（ＦＡＢＭＳ）可确定多肽的分子量，而在此基础上采用活化碰撞（ＣＡ）技术可对氨基酸的序列进行识别。     

The Studies of Fast Atom Bombardment Mass Spectrometry of Melezitose Derivatives

Melezitose is a kind of nonreducing sugar, its structure is 3-(α-D-glucopyranosyl)-β-D-fructofuranosyl-α-D-glucopyranose, it is a principal constituent of Alhagi pseudalhagi Desv.manna, which is used as a drug in Uygur medicine.     

胆汁酸及其丁二酸衍生物的快速原子轰击质谱

本文研究游离胆汁酸及其丁二酸衍生物的快速原子轰击(FAB)质谱.用甘油或硫甘醇作样品的基质,具有不同的灵敏度增强效应。FAB负离子质谱,获得[M-n]^-典型离子簇,[M-1]^-作为最强离子是每一个样品的基峰.     

Fast Atom Bombardment Mass Spectrometry of Organophosphorus Compounds

Abstract

Fast atom bombardment mass spectrometry has been applied to a range of ionic, zwitterionic, and thermally labile organophosphorus compounds and has been shown to be a potentially valuable aid to identification and characterisation. Results are presented for the positive ion spectra of quasiphosphonium salts, aminophosphonic, aminophosphonous, and aminophosphinic acids, phosphonopeptides, and a number of heat sensitive derivatives. The quasiphosphonium intermediates derived from alkyl esters of phosphorus (III) acids and halogeno compounds generally show base peaks corresponding to the phosphonium ion which fragments to give the protonated form of the Arbuzov product. Strong characteristic peaks are also obtained from various phosphonic and phosphinic derivatives. α- and ω-aminoalkanephosphonic acids and their guanidino analogues give base peaks corresponding to [M+H]⁺ ions and show simple fragmentations arising mainly from the loss of HPO₃ and H₃PO₃ Phosphonous derivatives give peaks corresponding to [M+H]⁺ and [2M+H]⁺ with the base peak apparently resulting from the elimination of HPO₃ from the dimeric structure. Elimination of H₃PO₂ is also indicated. Examples of phosphonopeptides are also shown to give base peaks at [M+H]⁺ and to exhibit characteristic fragmentations that are of potential value as aids to identification. Fast atom bombardment mass spectra have also been recorded for a number of pesticidal phosphorodithioates, their principal metabolites, and some related esters. Although [M+H]⁺ peaks are clearly present in all cases, the intensity is variable and fragmentations are generally more complex than those obtained for the compounds referred to above. O,O-Diethyl phosphorodithioates, for example, frequently give rise to (EtO)₂PS⁺, which fragments further by stepwise elimination of ethylene as is also observed in electron impact mass spectrometry. We are grateful to SERC for support of this work and for FAB mass spectrometry facilities at the Physico-Chemical Measurements Unit, Harwell.     

三氟乙酸金属盐的快原子轰击质谱研究

本文报道了Ｍ（ＯＯＣＣＦ３）ｍ（Ｍ＝Ｎａ、Ｋ、Ｍｇ、Ｃａ、Ａｌ）在三乙醇胺中的正负离子ＦＡＢ谱。谱的主要特征反映了该化合物在溶液中的离解行为，可作为这类盐质谱鉴定的依据。     

The Measurement of Leucine Enkephalinat the Femtomole Level by Fast Atom Bombardment Mass Spectrometry/Mass Spectrometry Methods

Abstract

FAB-MS/MS methods are used to quantify the neuropeptide leucine enkephalin (LE = YGGFL) in synthetic solutions. Maximum molecular specificity is provided by monitoring two metastable transitions from the LE (M + H)⁺, 556 → 425 and 556 → 336, in a forward geometry (E, B) mass spectrometer using a B/E linked-field selected reaction monitoring technique. Obtained sensitivity is 40 pg LE, which equals 72 fmol. The statistics of the best-fit straight lines are, for m/z 425: y = 34 + 166 (r = 0.999), and for m/z 336: y = 2.5x + 17.2 (r = 0.996).     

寡糖快原子轰击质谱中碱金属加合离子应用技术的研究

生命科学的研究成果^[1～3]表明,糖蛋白和糖脂中的糖基可作为细胞的识别信号,能控制细胞的分裂和分化.快原子轰击(FAB)质谱是测定寡糖的重要手段^[4,5],但目前还存在不少问题.我们在对麦芽各糖的研究中.