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1.
Direct analysis in real time (DART) is a recently developed ambient ionization technique for mass spectrometry to enable rapid and sensitive analyses with little or no sample preparation. After swab-based field sampling, the organothiophosphate malathion was analyzed using DART-Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) and tandem mass spectrometry (MS/MS). Mass resolution was documented to be over 800,000 in full-scan MS mode and over 1,000,000 for an MS/MS product ion produced by collision-induced dissociation of the protonated analyte. Mass measurement accuracy below 1 ppm was obtained for all DART-generated ions that belonged to the test compound in the mass spectra acquired using only external mass calibration. This high mass measurement accuracy, achievable at present only through FTMS, was required for unequivocal identification of the corresponding molecular formulae. 相似文献
2.
Lucy Lim Fangzhi Yan Stephen Bach Katianna Pihakari David Klein 《International journal of molecular sciences》2016,17(1)
Unknown compounds in environmental samples are difficult to identify using standard mass spectrometric methods. Fourier transform mass spectrometry (FTMS) has revolutionized how environmental analyses are performed. With its unsurpassed mass accuracy, high resolution and sensitivity, researchers now have a tool for difficult and complex environmental analyses. Two features of FTMS are responsible for changing the face of how complex analyses are accomplished. First is the ability to quickly and with high mass accuracy determine the presence of unknown chemical residues in samples. For years, the field has been limited by mass spectrometric methods that were based on knowing what compounds of interest were. Secondly, by utilizing the high resolution capabilities coupled with the low detection limits of FTMS, analysts also could dilute the sample sufficiently to minimize the ionization changes from varied matrices. 相似文献
3.
Zaima N Hayasaka T Goto-Inoue N Setou M 《International journal of molecular sciences》2010,11(12):5040-5055
Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is a powerful tool that enables the simultaneous detection and identification of biomolecules in analytes. MALDI-imaging mass spectrometry (MALDI-IMS) is a two-dimensional MALDI-mass spectrometric technique used to visualize the spatial distribution of biomolecules without extraction, purification, separation, or labeling of biological samples. MALDI-IMS has revealed the characteristic distribution of several biomolecules, including proteins, peptides, amino acids, lipids, carbohydrates, and nucleotides, in various tissues. The versatility of MALDI-IMS has opened a new frontier in several fields such as medicine, agriculture, biology, pharmacology, and pathology. MALDI-IMS has a great potential for discovery of unknown biomarkers. In this review, we describe the methodology and applications of MALDI-IMS for biological samples. 相似文献
4.
S. Mariccor A. B. Batoy Sabine Borgmann Karin Flick Josephine Griffith Jeffrey J. Jones Viswanathan Saraswathi Alyssa H. Hasty Peter Kaiser Charles L. Wilkins 《Lipids》2009,44(4):367-371
Here we describe a study of the feasibility of lipid and phospholipid (PL) profiling using matrix assisted laser desorption/ionization
(MALDI) Fourier transform mass spectrometry (FTMS) for two different applications. In this work PL profiles of different mammalian
tissues as well as those of whole cell organisms were examined. In particular, comparative analysis of lipid and PL profiles
of tissues from mice fed different diets was done and, in another application, MALDI FTMS was used to analyze PL profiles
of genetically modified Saccharomyces cerevisiae. Computational sorting of the observed ions was done in order to group the lipid and PL ions from complex MALDI spectra.
The PL profiles of liver tissues from mice fed different diets showed a cross correlation coefficient of 0.2580, indicating
significant dissimilarity, and revealed more than 30 significantly different peaks at the 99.9% confidence level. Histogram
plots derived from the spectra of wild type and genetically modified yeast resulted in a cross correlation coefficient 0.8941
showing greater similarity, but still revealing a number of significantly different peaks. Based on these results, it appears
possible to use MALDI FTMS to identify PLs as potential biomarkers for metabolic processes in whole cells and tissues. 相似文献
5.
Ryuji Hiraguchi Hisanao Hazama Kenichirou Senoo Yukinori Yahata Katsuyoshi Masuda Kunio Awazu 《International journal of molecular sciences》2014,15(6):10821-10834
A continuous flow atmospheric pressure laser desorption/ionization technique using a porous stainless steel probe and a 6–7-µm-band mid-infrared tunable laser was developed. This ion source is capable of direct ionization from a continuous flow with a high temporal stability. The 6–7-µm wavelength region corresponds to the characteristic absorption bands of various molecular vibration modes, including O–H, C=O, CH3 and C–N bonds. Consequently, many organic compounds and solvents, including water, have characteristic absorption peaks in this region. This ion source requires no additional matrix, and utilizes water or acetonitrile as the solvent matrix at several absorption peak wavelengths (6.05 and 7.27 µm, respectively). The distribution of multiply-charged peptide ions is extremely sensitive to the temperature of the heated capillary, which is the inlet of the mass spectrometer. This ionization technique has potential for the interface of liquid chromatography/mass spectrometry (LC/MS). 相似文献
6.
Julia K. Prunsa Claudius Rapp Ulrich Hintze Klaus‐Peter Wittern Wilfried A. Knig 《European Journal of Lipid Science and Technology》2003,105(6):275-280
Laser desorption/ionization time‐of‐flight mass spectrometry (LDI‐TOF MS) followed by evaluation of the mass spectra with principal component analysis (PCA) was used for the in‐depth characterization of paraffin oils (mineral oils) and petrolatum (paraffin jelly) samples. These raw materials are liquid and semisolid mixtures of hydrocarbons obtained from petroleum. Mass spectrometric analysis was done using a solvent‐free sample preparation with silver trifluoroacetate. The analysis was carried out on a commercially available matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometer. Mass spectra were evaluated using parameters calculated from the areas of different alkane and cycloalkane species and by PCA. The ratios between specific peak areas were chosen as PCA‐input data instead of the less reproducible absolute peak areas. The principal components enable comparison of a large number of samples and can also be used for visualization of data. In this work, it is clearly demonstrated that combining LDI‐TOF MS and PCA provides a fast and efficient tool for the characterization of paraffin oils and petrolatum. Petrolatum and four different kinds of paraffin oil were analyzed and the results compared with other analytical methods. 相似文献
7.
采用3-氨基喹啉(3-AQ)、二元基体3-AQ/2,5-二羟基苯甲酸(DHB)及常用于糖类物质测定的DHB和二元基体DHB/1-羟基异喹啉(1-HIQ)对一天然提取植物糖样进行了基体辅助激光解吸/电离飞行时间质谱(MALDI-TOF MS)分析。实验结果表明:此植物糖样由线形和环形聚己糖组成,其最大分子量至少达3000 Da;3-AQ与常用基体DHB及DHB/HIQ相比较,能提供更准确、更全面的样品组成及分子结构信息,且具有优越于常用基体解吸电离环状糖分子的能力。 相似文献
8.
Melissa A. Anderson Ledelle Collier Robert Dilliplane Folahan O. Ayorinde 《Journal of the American Oil Chemists' Society》1993,70(9):905-908
Vernonia galamensis seed oil is a natural source of epoxidized triacylglycerols, which consist of 52% trivernolin and a mixture of other triacylglycerols.
Epoxidized oils are used for industrial applications, such as coatings and plastic formulations. To determine the major molecular
species present in Vernonia oil, desorption chemical ionization/mass spectrometry and mass spectrometry/mass spectrometry
were used to determine its glyceride composition. Seven triacylglycerols predominated: divernoloylarachidonate, trivernolin,
divernoloylstearate, divernoloyloleate, divernoloyllinoleate, dilinolenoyl vernolate and divernoloylpalmitate. 相似文献
9.
Anna L. Kaysheva Pavel A. Frantsuzov Arthur T. Kopylov Tatyana O. Pleshakova Alexander A. Stepanov Kristina A. Malsagova Alexander I. Archakov Yurii D. Ivanov 《International journal of molecular sciences》2021,22(1)
An approach to highly-sensitive mass spectrometry detection of proteins after surface-enhanced concentrating has been elaborated. The approach is based on a combination of mass spectrometry and atomic force microscopy to detect target proteins. (1) Background: For this purpose, a technique for preliminary preparation of molecular relief surfaces formed as a result of a chemical or biospecific concentration of proteins from solution was developed and tested on several types of chip surfaces. (2) Methods: mass spectrometric identification of proteins using trailing detectors: ion trap, time of flight, orbital trap, and triple quadrupole. We used the electrospray type of ionization and matrix-assisted laser desorption/ionization. (3) Results: It is shown that when using locally functionalized atomically smooth surfaces, the sensitivity of the mass spectrometric method increases by two orders of magnitude as compared with measurements in solution. Conclusions: It has been demonstrated that the effective concentration of target proteins on specially prepared surfaces increases the concentration sensitivity of mass spectrometric detectors—time-of-flight, ion trap, triple quadrupole, and orbital ion trap in the concentration range from up to 10−15 M. 相似文献
10.
Potassium Ionization of Desorbed Species (K+IDS) with mass spectrometric detection is an extremely useful tool for the characterization of high performance organic coatings. K+IDS uses a commercial rapid heating probe to desorb intact molecules which are then ionized by potassium cation attachment. Based upon the molecular ions, which appear as [M]K+, coatings components can be qualitatively and quantitatively analyzed. In this work K+IDS was selected as a method of soft ionization (i.e. producing molecular ions) because of its simplicity, wide applicability, low cost and compatibility with the quadrupole mass spectrometer. This presentation reports the application of K+IDS to polymer additives (UV stabilizers and antioxidants), catalysts (organotin), reactive diluents (vernonia oil and aliphatic epoxides) and polyurethane precursors (polyesters and isocyanates). 相似文献
11.
Christopher Barner-Kowollik Author Vitae Thomas P. Davis Author VitaeAuthor Vitae 《Polymer》2004,45(23):7791-7805
The present feature article provides an overview on the use of state-of-the-art mass spectrometry techniques such as matrix assisted laser desorption and ionization time of flight (MALDI-TOF) mass spectrometry as well as electrospray ionization mass spectrometry (ESI-MS) for probing the mechanism of free radical polymerization processes. The article features representative examples of the application of mass spectrometry techniques to conventional free radical polymerization, nitroxide mediated polymerization (NMP), atom transfer radical polymerization (ATRP), reversible addition fragmentation chain transfer (RAFT) as well as catalytic chain transfer (CCT) processes. 相似文献
12.
Analysis of the polyethylene glycol glucosides and FA esters thereof by atmospheric-pressure ionization MS 总被引:1,自引:0,他引:1
Polyethylene glycol (PEG) glucosides (PEGG) and the PEGG esters of lauric acid were analyzed by atmospheric-pressure ionization
MS (API-MS) with electrospray ionization. Straightforward mass characterization of the complex mixtures could be achieved
without prior chromatographic separation. The constituents were identified on the basis of quasi-molecular ions. Individual
components could be observed as protonated molecular ions [M+H]+ and/or as their NH4
+, Na+, or K+ adducts in positive ion mode. The mass spectrometric investigation showed that mixtures of PEGG consisted of monoglucoside,
diglucoside, polyglucoside, and free PEG. The esterification product is a mixture of two types of nonionic surfactants: PEG-laurates
and PEGG-laurates. The reasons for distortion of the quasi-molecular ion intensities and the stabilization of adduct ions
were discussed. The rapid and highly sensitive API-MS analysis technique proposed here is well suited for direct characterization
of complex mixtures and suitable for development as a routine analytical method. 相似文献
13.
14.
R. A. Sanders D. R. Gardner M. P. Lacey T. Keough 《Journal of the American Oil Chemists' Society》1992,69(8):760-771
Field desorption (FD), fast atom bombardment (FAB) and plasma desorption (PD) mass spectrometry have been used for the characterization
of olestra, a mixture of octa-, hepta- and hexaesters of sucrose formed by reaction of sucrose with long-chain fatty acids
(C12–C18). Most previous applications of desorption ionization mass spectrometry have involved polar compounds; however, the relatively
low-polarity olestra is also amenable to these techniques with proper sample preparation. Field desorption provides molecular
weight information, but the transience of the signals limits the usefulness for observing fragmentation and measuring ester
distributions. In addition, FD may not be sensitive enough to allow characterization of fractions isolated from analytical
high-performance liquid chromatography (HPLC) columns. Fast atom bombardment produces longer-lasting signals, which permit
characterization of components over a wide mass range. However, signal-to-noise fluctuates substantially, depending on analyte
solubility in the matrix, making the characterization of partial esters collected from HPLC uncertain and difficult. Plasma
desorption mass spectrometry is the easiest and most sensitive technique for olestra characterization but provides the lowest
mass resolution. Because it requires no more than a few μg of material, it is effective for the characterization of HPLC fractions.
Furthermore, it is the only method, of the three investigated, that allows detection of intact dimeric species having molecular
masses in the 3,000 to 5,000 dalton range. 相似文献
15.
16.
The expanding capabilities of mass spectrometry/mass spectrometry (m.s.-m.s.) in mixture analysis and its applications to fuel-related materials are illustrated. High and low collision energy m.s.-m.s. data obtained on reverse geometry and triple quadrupole spectrometers are given for coal-derived liquid (SRC II) and diesel particulate samples. The direct analysis capability of the m.s.-m.s. methodology and its limitations are illustrated for the identification of an aliphatic carboxylic acid in diesel paniculate. The selective ionization techniques of ammonia chemical ionization and negative chemical ionization are shown to be particularly useful in enhancing the specificity of m.s.-m.s. characterizations. Negative chemical ionization is used to confirm the presence of hydroxybenzoic acid in a diesel particulate sample. Combined laser desorption-chemical ionization is also demonstrated to be an effective ionization technique in m.s.-m.s. analysis. A variant of m.s.-m.s., in which selected anions fragment with charge inversion to give fragment cations, is also employed in the analysis of SRC II and used to identify thioaryl moieties. Functional group screening by an alternative m.s.—m.s. scan procedure, neutral loss scanning, is demonstrated for phenols in SRC II. A scan for all parent ions of a selected daughter ion provides a screening procedure for rapidly identifying all compounds of a given structural type in a complex mixture. The dependence of m.s.-m.s. spectra on collision energy and pressure is shown to add further detail to m.s.—m.s. analysis. The development of a library of m.s.—m.s. spectra of reference compounds to be used for the identification of individual constituents in fuel-related materials is described. 相似文献
17.
Negative ion mass spectrometric techniques, for compounds having good ionization properties, such as pentafluorobenzyl derivatives,
are believed to be more sensitive than positive ion methods. Preparation of PFB oximes of fatty aldehydes from crude lipid
extracts is problematic due to the release of free aldehydes from plasmalogens during derivatization. Accordingly, in these
studies plasmalogens were removed by silicic acid column chromatography prior to pentafluorobenzyl derivatization. This simple
purification step to remove plasmalogens is shown to facilitate the quantification of long-chain aldehydes by analysis of
their pentafluorobenzyl oxime derivatives utilizing gas chromatography–mass spectrometry in the negative ion chemical ionization
mode. The limit of detection for long chain fatty aldehydes using this method is 0.5 pmol and it is linear over two orders
of magnitude. Silicic acid column chromatography followed by electrospray ionization mass spectrometry demonstrated that plasmalogens
were removed (the detection limit for this analyses was ≤0.3 pmol). Furthermore, we have exploited the utility and sensitivity
of this method to identify increases in hexadecanal and octadecanal in 3-amino-1,2,4-triazole treated human neutrophils.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
中药黄芪中异黄酮苷类化合物的高效液相色谱-串联质谱分析 总被引:2,自引:0,他引:2
利用高效液相色谱-大气压化学电离质谱联用技术,建立了黄芪提取物中的有效成分毛蕊异黄酮-7-O-β-D-葡萄糖苷和芒柄花素-7-O-β-D-葡萄糖苷的定性分析方法。这两个化合物在大气压化学电离质谱条件下,质谱裂解行为的研究表明,二者具有相似的特征质谱裂解行为,即在正离子模式下的一级质谱中均产生强的准分子离子[M+H]+峰和苷元离子[M+H-G lu]+峰;且苷元离子经碰撞诱导解离均产生.CH3(15 Da)、CH3OH(32Da)和2CO(56 Da)的中性丢失;同时发生Retro-D iels A lder(RDA)裂解反应,导致在毛蕊异黄酮-7-O-β-D-葡萄糖苷和芒柄花素-7-O-β-D-葡萄糖苷的二级质谱图中分别产生相对分子质量为m/Z148和m/Z133的特征碎片离子峰。这些特征碎片可以作为这两个化合物定性的依据。该方法已成功应用于黄芪注射液中的这两种物质的定性分析。 相似文献
19.
Pia Sala Sandra P?tz Martina Brunner Martin Tr?tzmüller Alexander Fauland Alexander Triebl Jürgen Hartler Ernst Lankmayr Harald C. K?feler 《International journal of molecular sciences》2015,16(4):8351-8363
A novel liquid chromatography-mass spectrometry (LC-MS) approach for analysis of oxidized phosphatidylcholines by an Orbitrap Fourier Transform mass spectrometer in positive electrospray ionization (ESI) coupled to hydrophilic interaction liquid chromatography (HILIC) was developed. This method depends on three selectivity criteria for separation and identification: retention time, exact mass at a resolution of 100,000 and collision induced dissociation (CID) fragment spectra in a linear ion trap. The process of chromatography development showed the best separation properties with a silica-based Kinetex column. This type of chromatography was able to separate all major lipid classes expected in mammalian samples, yielding increased sensitivity of oxidized phosphatidylcholines over reversed phase chromatography. Identification of molecular species was achieved by exact mass on intact molecular ions and CID tandem mass spectra containing characteristic fragments. Due to a lack of commercially available standards, method development was performed with copper induced oxidation products of palmitoyl-arachidonoyl-phosphatidylcholine, which resulted in a plethora of lipid species oxidized at the arachidonoyl moiety. Validation of the method was done with copper oxidized human low-density lipoprotein (LDL) prepared by ultracentrifugation. In these LDL samples we could identify 46 oxidized molecular phosphatidylcholine species out of 99 possible candidates. 相似文献
20.
Liquid chromatography–atmospheric pressure chemical ionization mass spectrometry (LC–MS/APCI) with a chiral phase was used for separation of triacylglycerols (TAG) obtained either by organic synthesis or isolated from different algal species. We present chromatographic characteristics and tandem mass spectra of enantiomers and positional isomers (regioisomers) of C16, C18 and C20 polyunsaturated fatty acids. The retention time was found to depend on the structure of the given TAG, increasing with increasing number of double bonds and decreasing with increasing number of the carbons in TAG, with the exception of dieicosapentaenoyl‐palmitoyl‐glycerols. 相似文献