How does the molecular velocity distribution affect kinetics measurements by time-resolved mass spectrometry?

2007 ◽  
Vol 39 (10) ◽  
pp. 565-570 ◽  
Author(s):  
Craig A. Taatjes
Keyword(s):  
Mass Spectrometry ◽  
Velocity Distribution ◽  
Time Resolved ◽  
Molecular Velocity

scholarly journals Synthesis, Biomacromolecular Interactions, Photodynamic NO Releasing and Cellular Imaging of Two [RuCl(qn)(Lbpy)(NO)]X Complexes

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2545
Author(s):  
Luna Song ◽  
Hehe Bai ◽  
Chenyang Liu ◽  
Wenjun Gong ◽  
Ai Wang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Confocal Imaging ◽  
Epr Spectra ◽  
Distorted Octahedral Geometry ◽  
Ionization Mass ◽  
Time Resolved ◽  
Pbr322 Dna ◽  
Vis Spectroscopy ◽  
No Release ◽  
Ft Ir

Two light-activated NO donors [RuCl(qn)(Lbpy)(NO)]X with 8-hydroxyquinoline (qn) and 2,2′-bipyridine derivatives (Lbpy) as co-ligands were synthesized (Lbpy1 = 4,4′-dicarboxyl-2,2′-dipyridine, X = Cl− and Lbpy2 = 4,4′-dimethoxycarbonyl-2,2′-dipyridine, X = NO3−), and characterized using ultraviolet–visible (UV-vis) spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (1H NMR), elemental analysis and electrospray ionization mass spectrometry (ESI-MS) spectra. The [RuCl(qn)(Lbpy2)(NO)]NO3 complex was crystallized and exhibited distorted octahedral geometry, in which the Ru–N(O) bond length was 1.752(6) Å and the Ru–N–O angle was 177.6(6)°. Time-resolved FT-IR and electron paramagnetic resonance (EPR) spectra were used to confirm the photoactivated NO release of the complexes. The binding constant (Kb) of two complexes with human serum albumin (HSA) and DNA were quantitatively evaluated using fluorescence spectroscopy, Ru-Lbpy1 (Kb~106 with HSA and ~104 with DNA) had higher affinity than Ru-Lbpy2. The interactions between the complexes and HSA were investigated using matrix assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF-MS) and EPR spectra. HSA can be used as a carrier to facilitate the release of NO from the complexes upon photoirradiation. The confocal imaging of photo-induced NO release in living cells was successfully observed with a fluorescent NO probe. Moreover, the photocleavage of pBR322 DNA for the complexes and the effect of different Lbpy substituted groups in the complexes on their reactivity were analyzed.

MASS AND LIFETIME MEASUREMENTS AT THE PRESENT ESR FACILITY

2009 ◽  
Vol 18 (02) ◽  
pp. 323-334 ◽  
Author(s):  
YURI A. LITVINOV
Keyword(s):  
Mass Spectrometry ◽  
Single Particle ◽  
Experimental Methods ◽  
Lifetime Measurements ◽  
Time Resolved ◽  
Particle Decay ◽  
Decay Properties ◽  
Decay Spectroscopy ◽  
Beta Decays ◽  
Charged Ions

Mass and lifetime measurements of stored exotic nuclei is one of the successful experimental programs at the FRS-ESR facility of GSI, Darmstadt. Two experimental techniques, namely Isochronous and time-resolved Schottky mass spectrometry have been developed. Nuclides in a very broad range of half-lives starting from stable down to only a few ten microseconds can be addressed. Single stored ions can be measured which makes these techniques highly efficient. More than 1100 atomic masses have been measured meanwhile. Half-life measurements are performed with bare and few-electron ions. Decay properties of such highly-charged ions can be dramatically different from the ones known in neutral atoms. Single-particle decay spectroscopy has been developed for investigations of two-body beta decays. A brief description of the experimental methods and recent results will be presented. Future experiments at the present facility and the perspectives with the new NuSTAR/ILIMA project at FAIR will be outlined.

Time-Resolved Micro Liquid Desorption Mass Spectrometry: Mechanism, Features, and Kinetic Applications

2006 ◽  
Vol 59 (2) ◽  
pp. 81 ◽  
Author(s):  
Ales Charvat ◽  
Andreas Bógehold ◽  
Bernd Abel
Keyword(s):  
Mass Spectrometry ◽  
Liquid Phase ◽  
High Speed ◽  
High Performance ◽  
Kinetic Studies ◽  
Solution Concentration ◽  
Bulk Water ◽  
Laser Wavelength ◽  
Time Resolved ◽  
Desorption Mass Spectrometry

Liquid water beam desorption mass spectrometry is an intriguing technique to isolate charged molecular aggregates directly from the liquid phase and to analyze them employing sensitive mass spectrometry. The liquid phase in this approach consists of a 10 µm diameter free liquid filament in vacuum which is irradiated by a focussed infrared laser pulse resonant with the OH-stretch vibration of bulk water. Depending upon the laser wavelength, charged (e.g. protonated) macromolecules are isolated from solution through a still poorly characterized mechanism. After the gentle liquid-to-vacuum transfer the low-charge-state aggregates are analyzed using time-of-flight mass spectrometry. A recent variant of the technique uses high performance liquid chromatography valves for local liquid injections of samples in the liquid carrier beam, which enables very low sample consumption and high speed sample analysis. In this review we summarize recent work to characterize the ‘desorption’ or ion isolation mechanism in this type of experiment. A decisive and interesting feature of micro liquid beam desorption mass spectrometry is that — under certain conditions — the gas-phase mass signal for a large number of small as well as supramolecular systems displays a surprisingly linear response on the solution concentration over many orders of magnitude, even for mixtures and complex body fluids. This feature and the all-liquid state nature of the technique makes this technique a solution-type spectroscopy that enables real kinetic studies involving (bio)polymers in solution without the need for internal standards. Two applications of the technique monitoring enzyme digestion of proteins and protein aggregation of an amyloid model system are highlighted, both displaying its potential for monitoring biokinetics in solution.

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