As is well documented, platinum nanoparticles, promising for catalysts for fuel cells, exhibit better catalytic activities, when alloyed with Zn. Pre-existing syntheses of Pt-Zn alloy catalysts are composed of a number of complex steps. In this study, we have demonstrated that nanoparticles of Pt-Zn alloys are simply generated by electron-beam irradiation in a transmission electron microscope o...

A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine thirteen pyrethroid insecticide residues in goat tissues (liver, kidney, muscle and heart) and milk using gas chromatography electron ionization mass spectrometry method (GC-MS). The samples were pre-concentrated using C18 packing material (dispersion adsorbent), followed by clean u...

Keto-enol tautomerism was investigated for ionized pyruvic acid using the DFT(B3LYP) method and the larger basis sets [6-31++G(d,p), 6-311++G(3df, 3pd) and aug-cc-pVDZ]. Change of the tautomeric preference was observed when going from the neutral to ionized tautomeric mixture. Ionization favors the enolization process (ketoenol) of pyruvic acid, whereas the ketonization (ketoenol) is preferred ...

introduction: delivering maximum dose to tumor and minimum dose to normal tissues is the most important goal in radiotherapy. according to icru, the maximum acceptable uncertainty in the delivered dose compared to the prescribed dose should be lower than 5%, and this is because of the relationship between absorbed dose, tumor control and normal tissue damage. absorbed dose accuracy is investiga...

Paper spray (PS) ionization, an ambient ionization method, has previously been explored as a direct and fast method for mass spectrometric analysis of complex mixtures. It has been applied to the analysis of a wide variety of compounds, mostly small molecules. The work reported here extends the application of PS ionization to noncovalent protein complexes on an ion mobility tandem mass spectrom...

amide-iminol tautomerism was studied for ionized oxamic acid (oa+•) in the gas phase using thedft method with the ub3lyp functional and various basis sets {6-31++g(d,p), 6-311+g(d,p), and augcc-pvdz}. among twenty tautomers-rotamers possible for oa+•, eleven isomers were found to bethermodynamically stable. similarly as for the neutral molecule, ionization (oa → oa+• + e) favors theamidization ...

Ionization suppression can be defined as the decrease of photoinduced atomic ionization rates with an increased applied field intensity. The temporal and spatial intensity distribution of a focused laser pulse introduces difficulty in observing ionization suppression. An analysis of the effect of a temporally Gaussian laser pulse on ionization suppression from Rydberg levels is given. It is fou...

Ambient ionization is a set of mass spectrometric ionization techniques performed under ambient conditions that allows the direct analysis of sample surfaces with little or no sample pretreatment. Using combinations of different types of sample introduction systems and ionization methods, several novel techniques have been developed over the last few years with many applications (e.g., food saf...