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[en] The establishment of a mass mobility correlation for ions of the series H⁺ (H₂O)sub(n) obtained by means of a device whereby a reaction chamber operating under atmospheric pressure is coupled with a mass spectrometer, has enabled to observe the transition between discrete mobilities of ions H⁺ (H₂O)₄ and H⁺ (H₂O)₅ and a mean mobility corresponding to the equilibrium

[en] Increased terrorist threat in recent years makes it especially important to improve the custom equipment including the development of ion mobility spectrometers for reliable, realtime and sensitive identification of illicit substances. The paper summarizes different approaches used in recent developments in the last years: statistical analysis, sampling automation and construction materials study. (paper)

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[en] A drift tube-mass spectrometer was used to measured the mobility of CH₅⁺, C₂H₅⁺ and C₃H₅⁺ in CH₄ over a wide range of the reduced field strength, E/N, from 15 to 500 Td (1 Td = 10^-17 V cm²). The zero-field mobilities of these ions turn out to be lower than those predicted by Langevin's polarization-limit theory. The low field mobilities for the first two ions are in good agreement with previous values obtained from other techniques. For E/N > 100 Td, the mobility of CH₅⁺ is lower than that of C₂H₅⁺ sm-bullet suggesting a proton transfer process between CH₅⁺ and CH₄. The mobility curves show a pronounced maximum over the range 200-300 Td

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[en] Relative proton affinities are usually measured by means of high pressure mass spectrometry. In this work ion mobility spectrometry was used to determine proton affinities. The standard molar enthalpy change ΔH⁰_M for the reaction MH⁺+N[rlhar2]M+NH⁺ was found to be: -(56.3±0.8) kJ·mol^-1, when M was ethyl acetate and N ethanol; -(27.8±0.5) kJ·mol^-1, when M was acetophenone and N ethyl acetate; -(10.6±0.2) kJ·mol^-1, when M was cycloheptanone and N ethyl acetate; -(66.1±1.2) kJ·mol^-1, when M was dimethyl methyl phosphonate and N ethyl acetate; and, -(56.7±0.9) kJ·mol^-1, when M was dimethyl methyl phosphonate and N cycloheptanone. These values are internally consistent and in good agreement with results obtained with high pressure mass spectrometry. On the basis of proton affinities of cycloheptanone and ethyl acetate, an absolute proton affinity of (902±1.2) kJ·mol^-1 has been determined for dimethyl methyl phosphonate

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[en] Recently it was created that the beam transmitted through insulator capillary makes a few angular oscillations around the capillary axes direction. It is surprising because due to self organization the charged pattern at the capillary wall is created by such manner, that the ions move along capillary axes after deviation from this pattern. Simple model of the beam angular oscillations at the insulator capillary exit is suggested in this work. Only one charged pattern exists when the stationary regime is achieved. But at the beginning of charging up the region behind this pattern also is charged up. The leakage current depends on charge density at the capillary wall very sharply. And this is the reason why small charge behind the pattern exists longer then the charge of the main pattern comes to saturation. So we have the retardation of discharging of the remote part in respect to basic pattern saturation, and the full charge exceed that is necessary for deviation the beam at the value of incident angle. The beam comes down from top side of capillary. When the extra charge of remote part disappears the beam comes back to the capillary axes. The beam makes more oscillations if the deviated beam touches down side of the capillary. (authors)