Electrospray-mass spectroscopy

The interaction of TPPTS with p-CD has been investigated in detail by uv-vis, circular dichorism, and NMR and electrospray mass spectroscopy [4,5]. The main conclusion of these studies is that one of the... 

Electrospray mass spectroscopy (EMS) is the mass spectroscopy of gaseous ions produced by electrospraying into a suitable gas at atmospheric pressure a dilute solution containing as solute the macromolecules in question. (Although the use of other gases is possible, we have obtained our best results with nitrogen gas.) Although the technique is... 

Figure 1. Schematic of a typical electrospray apparatus as used in electrospray mass spectroscopy (see text for explanation of dimensions)...

Ethyl acetate is used on the C18-adsorbed anthocyanins to remove polyphenolic compounds. More efficient polyphenolic recovery will be accomplished if residual water is removed from the cartridge with a nitrogen gas stream for 2 to 3 min before application of ethyl acetate. After washing the column with ethyl acetate, water should not be added because some anthocyanins could be eluted and lost. Ethyl acetate removal of polyphenolics is particularly recommended if the anthocyanin fraction is to be subsequently analyzed by electrospray mass spectroscopy. 

Other dendrimers that can be placed into this category are the dendritic silatrane wedges reported by Kemmitt and Henderson144 based on the building block 1. The dendrimers were synthesized up to the third generation and characterized using NMR spectroscopy and electrospray mass spectroscopy. 

The active species has also been observed experimentally by electrospray mass spectroscopy and the importance of the position of the transition state... 

Molar mass versus generation low-angle laser light scattering (LALLS) chemical ionization, fast atom bombardment, laser desorption and electrospray mass spectroscopy vapor phase osmometry electrophoresis. 

Structures 13C, 2H and 2H NMR spectroscopy (T2 relaxation times, signal intensity ratio versus generation) rheology studies electron microscopy computer-assisted molecular simulations, comparison to CPK models electrospray mass spectroscopy fluorescence probe analysis. 

Presently, defects of the type A and B are the only serious side-reactions encountered in the synthesis of Starburst PAMAM dendrimers (generation = 0-10) by the divergent initiator core method . Defects of the types C, D and E have been minimized to under 3-5 mole% per generation. Polydispersities (Mw/Mn) of 1.0007 have been routinely observed for Starburst PAMAM dendrimers (generation = 4 NH3 core) which has an empirical formula of C465H933N187093 and a calculated molecular weight of 10632, as verified by electrospray mass spectroscopy [169]. 

Zhou et al. reported the first cyclic voltammetric (CV) study of C60F48 in solution and showed that the reduction potential of C60F48 is more positive than that of the first reduction wave of C6o by 1.38 V [65]. This shift reflects exactly the change of the LUMO level of C6o upon fluorination as is shown in Fig. 19. Based on the CV behavior and electrospray mass spectroscopy, they proposed the following EECEEC mechanism for the first four reduction waves of C60F48. 

Phenoselenazine in a drybox under N2 atmosphere was combined with lithium diisopro-pylamide in THF. Trimethyloxonium tetrafluorobate (1 equivalent) was added slowly and the solution was stirred for 1 h. The solution was then quenched with methanol. Upon silica gel chromatography (20 1 methylene chloride-acetone), Me-PSZ (a white powder) was isolated. The compound was characterized with NMR, TLC, and electrospray mass spectroscopy (M + H 261.0). 

The compounds are prepared by a metathesis reaction from the corresponding iodide or bromide salt. The compounds are typically low melting point salts (in many cases molten at room temperature), which range from being quite hydrophobic (TFSA, PF ) to completely water soluble and hygroscopic (DCA, BF4). The purity of the samples is established via solution NMR, electrospray mass spectroscopy, and chemical analytical analysis. 

Cu(TpMe)2] prepared from the reaction of CuCl2 with K(TpMe) has been characterized by magnetic susceptibilities, fast atom bombardment and IR spectrometry, and X-ray single-crystal study.1 Cop-per(I) complexes containing water soluble phosphines, [Cu(TpMe)(L)] (L = 4- or 2-(diphenylphosphane)benzoic acid), have been characterized by IR in the solid state, and by NMR (JH and 31P 1H ) and electrospray mass spectroscopy in solution. Chemiluminescence technique was used to evaluate their superoxide scavenging activity.2... 

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