APPLICATIONS OF MEMBRANE EXTRACTION-MICROTRAP IN THE ANALYSIS OF ORGANIC MASS SPECTROMETRY

Theconcentrationofvolatileorganiccompounds(VOCs)inThesamplesisusuallyunderppblevel,andthesesamplesusuallycontainalargeamountofwater.ThismakesTheirdirectdeterminationdifficult.Typicalsamplepreparationmethodssuchalliquid-liquidextraction,steamdistillation,directhead-space,andpurge/trapmethodsforcollectingvolatileshavevariousdrawbacks.includingheavyandcomplicatedapparatus,costandexcessivepreparationtime.Onthebasisofourrecentworkswedesignedandmadeamembraneextractionmodule(ME)andaMicroTrap(MT)u…     

MASS SPECTROMETRY ANALYSIS OF DRUGS OF ABUSE: CHALLENGES AND EMERGING STRATEGIES

Mass spectrometry has been the “gold standard” for drugs of abuse (DoA) analysis for many decades because of the selectivity and sensitivity it affords. Recent progress in all aspects of mass spectrometry has seen significant developments in the field of DoA analysis. Mass spectrometry is particularly well suited to address the rapidly proliferating number of very high potency, novel psychoactive substances that are causing an alarming number of fatalities worldwide. This review surveys advancements in the areas of sample preparation, gas and liquid chromatography-mass spectrometry, as well as the rapidly emerging field of ambient ionization mass spectrometry. We have predominantly targeted literature progress over the past ten years and present our outlook for the future. © 2020 Periodicals, Inc. Mass Spec Rev     

THE USE OF MASS SPECTROMETRY TO STUDY ZN-METALLOPROTEASE-SUBSTRATE INTERACTIONS

Zinc metalloproteases (ZnMPs) participate in diverse biological reactions, encompassing the synthesis and degradation of all the major metabolites in living organisms. In particular, ZnMPs have been recognized to play a very important role in controlling the concentration level of several peptides and/or proteins whose homeostasis has to be finely regulated for the correct physiology of cells. Dyshomeostasis of aggregation-prone proteins causes pathological conditions and the development of several different diseases. For this reason, in recent years, many analytical approaches have been applied for studying the interaction between ZnMPs and their substrates and how environmental factors can affect enzyme activities. In this scenario, mass spectrometric methods occupy a very important role in elucidating different aspects of ZnMPs-substrates interaction. These range from identification of cleavage sites to quantitation of kinetic parameters. In this work, an overview of all the main achievements regarding the application of mass spectrometric methods to investigating ZnMPs-substrates interactions is presented. A general experimental protocol is also described which may prove useful to the study of similar interactions. © 2020 John Wiley & Sons Ltd. Mass Spec Rev     

ADVANCES IN HIGH-RESOLUTION MALDI MASS SPECTROMETRY FOR NEUROBIOLOGY

Research in the field of neurobiology and neurochemistry has seen a rapid expansion in the last several years due to advances in technologies and instrumentation, facilitating the detection of biomolecules critical to the complex signaling of neurons. Part of this growth has been due to the development and implementation of high-resolution Fourier transform (FT) mass spectrometry (MS), as is offered by FT ion cyclotron resonance (FTICR) and Orbitrap mass analyzers, which improves the accuracy of measurements and helps resolve the complex biological mixtures often analyzed in the nervous system. The coupling of matrix-assisted laser desorption/ionization (MALDI) with high-resolution MS has drastically expanded the information that can be obtained with these complex samples. This review discusses notable technical developments in MALDI-FTICR and MALDI-Orbitrap platforms and their applications toward molecules in the nervous system, including sequence elucidation and profiling with de novo sequencing, analysis of post-translational modifications, in situ analysis, key advances in sample preparation and handling, quantitation, and imaging. Notable novel applications are also discussed to highlight key developments critical to advancing our understanding of neurobiology and providing insight into the exciting future of this field. © 2020 John Wiley & Sons Ltd. Mass Spec Rev     

TUTORIAL: ION ACTIVATION IN TANDEM MASS SPECTROMETRY USING ULTRA-HIGH RESOLUTION INSTRUMENTATION

Tandem mass spectrometry involves isolation of specific precursor ions and their subsequent excitation through collision-, photon-, or electron-mediated activation techniques in order to induce unimolecular dissociation leading to formation of fragment ions. These powerful ion activation techniques, typically used in between mass selection and mass analysis steps for structural elucidation, have not only found a wide variety of analytical applications in chemistry and biology, but they have also been used to study the fundamental properties of ions in the gas phase. In this tutorial paper, a brief overview is presented of the theories that have been used to describe the activation of ions and their subsequent unimolecular dissociation. Acronyms of the presented techniques include CID, PQD, HCD, SORI, SID, BIRD, IRMPD, UVPD, EPD, ECD, EDD, ETD, and EID. The fundamental principles of these techniques are discussed in the context of their implementation on ultra-high resolution tandem mass spectrometers. © 2020 John Wiley & Sons Ltd. Mass Spec Rev     

TIG电弧传热传质过程的数值分析

以ＴＩＧ电弧为对象,建立了焊接电弧传热传质过程的完善数学模型,引入欧姆定律计算电流密度分布并用Ｋ－ε模型处理紊流问题。使用ＦＯＲＴＲＡＮ语言在ＳＵＮ工作站上进行了数值分析,得到了１００Ａ～３００Ａ电流下的流场分布、温度分布及电流分布等重要物理数据,且与重要的试验结果吻合良好。     

MASS SPECTROMETRY IN THE PYROLYSIS STUDY OF POLY(ARYL-ETHR-KEONE)

Poly(aryl-ether-ether-ketone)(PEEK)isknowntoresistorganicsolvents,chemicalcorrosion,ignition,andcanbereadilyadaptedforprocessing.ItisaThermoplasticpolymerwithhighThermaldurabilityandisapotentialcandidatetoreplaceconventionalthermallydurablematerialsandsparepartsusedinautomobileandaerospaceindustries.Therefore,ThereisanincreasingneedtounderstandThepyrolysis(Py)behaviorandmechanismofPEEK.PyrolysisusesheatalonetobreakdownlargemoleculesintomoleculesoflowermassduetoThermalfissionand,occasiona…     

LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY BOTTOM‐UP PROTEOMIC METHODS IN ANIMAL SPECIES ANALYSIS OF PROCESSED MEAT FOR FOOD AUTHENTICATION AND THE DETECTION OF ADULTERATIONS

This review offers an overview of the current status and the most recent advances in liquid chromatography–mass spectrometry (LC‐MS) techniques with both high‐resolution and low‐resolution tandem mass analyzers applied to the identification and detection of heat‐stable species‐speci?c peptide markers of meat in highly processed food products. We present sets of myofibrillar and sarcoplasmic proteins, which turned out to be the source of 105 heat‐stable peptides, detectable in processed meat using LC‐MS/MS. A list of heat‐stable species‐specific peptides was compiled for eleven types of white and red meat including chicken, duck, goose, turkey, pork, beef, lamb, rabbit, buffalo, deer, and horse meat, which can be used as markers for meat authentication. Among the 105 peptides, 57 were verified by multiple reaction monitoring, enabling identification of each species with high specificity and selectivity. The most described and monitored species by LC‐MS/MS so far are chicken and pork with 26 confirmed heat‐stable peptide markers for each meat. In thermally processed samples, myosin, myoglobin, hemoglobin, l ‐lactase dehydrogenase A and β‐enolase are the main protein sources of heat‐stable markers. © 2019 John Wiley & Sons Ltd. Mass Spec Rev     

DESIGN AND PERFORMANCE OF TWO ORTHOGONAL EXTRACTION TIME-OF-FLIGHT SECONDARY ION MASS SPECTROMETERS FOR FOCUSED ION BEAM INSTRUMENTS

The design and performance of two orthogonal extraction time-of-flight mass spectrometers are reported that were adapted to existing focused ion beam microscopes for secondary ion mass spectrometry. The performances of these designs were compared to that of a prototype previously described by our group. The differences include newly designed transfer ion optics and in the use of a larger microscope chamber. The two new prototypes allow a mass resolving power of either 600 Th/Th (compact design) or 3000 Th/Th (high resolution design) while simultaneously achieving a lateral spatial resolution of less than 50 nm. The spectrometers and their performance (effective ion yield, mass resolving power, lateral, and depth resolution) are described and compared. Additionally, example applications are presented with multivariate statistical methods to visualize the data sets. Both time-of-flight mass analyzers use orthogonal extraction which avoids the need to pulse the primary ion beam, and the of use monoisotopic gallium to preserve the mass resolution. The goal of the design was a cost-effective accessory to augment typical focused ion beam-scanning electron microscopy applications as an alternative to the cost of a dedicated secondary ion mass spectrometer. The modified instrument allows excellent non destructive imaging and easy sample access, and benefits from the presence of complementary non destructive analytical and imaging techniques that exploit the presence of an electron microscope.     

FRAGMENTATION ANALYSIS OF OLIGONUCLEOTIDES BY MATRIX-ASSISTED LASER DESORPTION/IONIZATION (MALDI) MASS SPECTROMETRY

CharacterizationofnucleicacidbyMatrix-assistedLaserDesorption/Ionizationmassspec-trometry(MALDI-MS)islimitedtorelativelysmalloligomers(<30-mer).SeveralfactorshavebeenproposedtoinfluenceThecapabilityoftheMALDIanalysisfornucleicacids.Thesefactorsinclude(a)thedesorption/ionizationefficiencyofanalyte,(b)thephysicaldistributionofanalyteinmatrix;and(c)theextentofanalytefragmentation.Asthepolyoligomeraslargeas150nucleotidesinlengthhavebeensuccessfullydetected1andtheanalyticalmassrangeandsensit…     

MINIATURIZATION IN MASS SPECTROMETRY

Expectations for continuous miniaturization in mass spectrometry are not declining for years. Portable instruments are highly welcome by the industry, science, space agencies, forensic laboratories, and many other units. All are striving for the small, cheap, and as good as possible instruments. This review describes the recent developments of miniature mass spectrometers and also provides selected applications where these devices are used. Upcoming perspectives of further development are also discussed. @ 2019 John Wiley & Sons Ltd. Mass Spec Rev     

STUDY ON THE MATRIX ASSISTED LASER DESORPTION IONIZATION TIME OF FLIGHT MASS SPECTROMETRY OF PHTHALOCYANINATO-POLYSILOXANE

PhthalocyaninesareapromisingclassofmaterialsforelectronicandphotonicdevicesduetoTheirsuperiorchemicalandphysicalstability.Co-planarface-to-facestackingofThesenconjugatedmacrocyclesleadstoextendedone-dimensionalsystemswithnewelectronicandopticalproperties.Thephthalocyaninato-polysiloxanehassuccessfullybeenusedinThefabricationofplanarphotodiodesandsensors[1,2].Somephthalocyaninato--polysiloxaneshaveshoweda'Shishkebab-likechirality'[3].Matrixassistedlaserdesorption/ionizationtimeofflightmassspe…     

LEAD ISOTOPE ANALYSIS BY MASS SPECTROMETRY AND ITS APPLICATION IN ARCHAEOMETRY

Source identification efforts by scientists to establish a boundary for a particular ore deposite used in the production of Bronze ABe copper artifacts have larsely failed for various mineralogical and metallurgical reasons. The isotopic composition of lead, an element presents in a minor amount in many copper ores and ts, is unchanged through physical and chemical processes and can be used to determine the sources of the copper used in copper and copper based bronze objects. Results show that for upper Euphrates, located in the eastern part of Turkey, Maden and Keban copper ores may have been an hnportant copper sources.     

MASS SPECTROMETRY IN VIROLOGICAL SCIENCES

Virology, as a branch of the life sciences, discovered mass spectrometry (MS) to be the pivotal tool around two decades ago. The technique unveiled the complex network of interactions between the living world of pro- and eukaryotes and viruses, which delivered “a piece of bad news wrapped in protein” as defined by Peter Medawar, Nobel Prize Laureate, in 1960. However, MS is constantly evolving, and novel approaches allow for a better understanding of interactions in this micro- and nanoworld. Currently, we can investigate the interplay between the virus and the cell by analyzing proteomes, interactomes, virus-cell interactions, and search for the compounds that build viral structures. In addition, by using MS, it is possible to look at the cell from the broader perspective and determine the role of viral infection on the scale of the organism, for example, monitoring the crosstalk between infected tissues and the immune system. In such a way, MS became one of the major tools for the modern virology, allowing us to see the infection in the context of the whole cell or the organism. © 2019 John Wiley & Sons Ltd. Mass Spec Rev     

CHARACTERIZATION OF LANTHANIDE-AMINO ACIDS COMPLEXES BY ELECTROSPRAY IONIZATION MASS SPECTROMETRY

Rareearthelements(REEs)arewidelyusedintheareasofagricultureasgrowthpromotionagentandmodemtechnologies.Rareearthelementsalsoplayapeculiarfunctioninnatureprocessing,suchasplantgrowthandfarmanimalsfeeding.Itisstillnotclearlyhowthelivingmatterscombinewithrareearthelements.Therearesomepublishedliteratures[1,2]whichhavecharacterizedREEscompoundsbyIR,X-mydiffractlonandNMRtechniques,butThemassspectrometryisnotusedinthisareaquiteoften.ThisworkpresentsThecharacterizationoflanthanide-aminoacidscomp…     

关于振动筛运动的变质量动力学分析方法

本文在振动筛机构的分析中,根据变质量动力学和非线性振动的观点,考虑由于物料跳动带来的质量变化,提出一种理论分析方法,得到筛体强迫振动的一次近似解。     

DESIGN OF A PORTABLE ELECTROTHERMAL VAPORIZATION FLAME ATOMIC EMISSION SPECTROMETRY DEVICE FOR FIELD ANALYSIS

A nontraditional, portable flame atomic emission spectrometry (FAES) device has been constructed using a welding industry metal cutting torch as the flame source with a tungsten coil electrothermal vaporization device for sample introduction. Twenty-microliter sample aliquots were pipetted onto a commercially available tungsten filament, and a home-written Visual Basic program was used to automatically dry and atomize the sample. The sample was then transported into the heart of the air-acetylene flame, where it was excited, and the resulting emission signal was focused onto the entrance of a miniature charge coupled device spectrometer. Figures of merit were determined for five alkaline and alkali earth metals of biological and environmental significance. Limits of detection were, on average, 100 times lower than those for traditional flame emission spectrometers. The capabilities of this portable device make it an ideal tool for biological field analysis, particularly in areas where traditional laboratories are inaccessible.