Thermal electron attachment to halogenated silanes in the gas phase.

Rationale: Silane derivatives play a crucial role in industrial plasma processes for the fabrication of various electronic devices such as lighting devices, solar cells, and displays. Accurate quantitative data are essential for modeling technological plasmas. This study reports the rate coefficients (k) and activation energies (E) for thermal electron attachment to SiCl, Si (CH)CHF, and SiCl (CH)Si(CH), which are key parameters for understanding the underlying processes in plasmas.

Analysis of positional isomers of 2-3-4-alkoxyphenylcarbamic acid derivatives by a combination of TLC and IMS.

In this study, we have demonstrated a separation of positional isomers of some derivatives of alkoxyphenylcarbamic acid. These compounds belong to drugs with local anesthetics activity. The low volatility compounds were analysed by a Thin Layer Chromatography (TLC) and Ion Mobility Spectrometry (IMS) using diode laser desorption for sample introduction to IMS.

Low Energy Electron Attachment by Some Chlorosilanes.

In this paper, the rate coefficients () and activation energies () for SiCl, SiHCl, and Si(CH)(CHCl)Cl molecules in the gas phase were measured using the pulsed Townsend technique. The experiment was performed in the temperature range of 298-378 K, and carbon dioxide was used as a buffer gas. The obtained depended on temperature in accordance with the Arrhenius equation.

Low-energy electron interactions with chlorotrimethylsilane (Si(CH ) Cl), dichlorodimethylsilane (Si(CH ) Cl ) and chloromethyldimethylsilane (SiH(CH ) (CH Cl)).

Rationale: Silane derivatives are widely used in industrial plasmas for manufacturing lighting devices, solar cells, displays, etc. Models of technological plasmas require quantitative data. The rate coefficients (k) and the activation energies (E ) of thermal electron attachment for chlorotrimethylsilane (Si(CH ) Cl), dichlorodimethylsilane (Si(CH ) Cl ) and chloromethyldimethylsilane (SiH(CH ) (CH Cl)) are reported.

Online detection and measurement of elemental mercury vapor by ion mobility spectrometry with chloroform dopant.

A rapid and simple method is proposed for detection of elemental mercury (Hg) vapor by ion mobility spectrometry (IMS). Negative corona discharge (CD) as the ionization source and chloroform as the dopant gas were used to produce Cl reactant ion. A mass spectrum of the product ions confirmed that the mechanism of ionization is based on Cl anion attachment to Hg and formation of HgCl ion.

Ion chemistry of phthalates in selected ion flow tube mass spectrometry: isomeric effects and secondary reactions with water vapour.

Phthalates are widely industrially used and their toxicity is of serious environmental and public health concern. Chemical ionization (CI) analytical techniques offer the potential to detect and monitor traces of phthalate vapours in air or sample headspace in real time. Promising techniques include selected ion flow tube mass spectrometry (SIFT-MS), proton transfer reaction mass spectrometry (PTR-MS) and ion mobility spectrometry (IMS).

Isomer and conformer selective atmospheric pressure chemical ionisation of dimethyl phthalate.

In this work we have studied the ionisation mechanism of Atmospheric Pressure Chemical Ionisation (ACPI) for three isomers of dimethyl phthalate (dimethyl phthalate - DMP (ortho- isomer), dimethyl isophthalate - DMIP (meta) and dimethyl terephthalate - DMTP (para)) using Ion Mobility Spectrometry (IMS) and IMS combined with an orthogonal acceleration Time of Flight Mass Spectrometer (oa-TOF MS). The molecules were chemically ionised using reactant ions H·(HO) (n = 3 and 4). The positive IMS and IMS-oaTOF mass spectra of the isomers showed significant differences in the ion mobilities and in the ion composition.

Effect of Basicity and Structure on the Hydration of Protonated Molecules, Proton-Bound Dimer and Cluster Formation: An Ion Mobility-Time of Flight Mass Spectrometry and Theoretical Study.

Protonation, hydration, and cluster formation of ammonia, formaldehyde, formic acid, acetone, butanone, 2-ocatanone, 2-nonanone, acetophenone, ethanol, pyridine, and its derivatives were studied by IMS-TOFMS technique equipped with a corona discharge ion source. It was found that tendency of the protonated molecules, MH, to participate in hydration or cluster formation depends on the basicity of M. The molecules with higher basicity were hydrated less than those with lower basicity.

Study of Atmospheric Pressure Chemical Ionization Mechanism in Corona Discharge Ion Source with and without NH Dopant by Ion Mobility Spectrometry combined with Mass Spectrometry: A Theoretical and Experimental Study.

Ionization of 2-nonanone, cyclopentanone, acetophenone, pyridine, and di- tert-butylpyridine (DTBP) in a corona discharge (CD) atmospheric pressure chemical ionization (APCI) ion source was studied using ion mobility (IMS) and time-of-flight mass spectrometry (TOF-MS). The IMS and MS spectra were recorded in the absence and presence of ammonia dopant. Without NH dopant, the reactant ion (RI) was H(HO) , n = 3,4, and the MH(HO) clusters were produced as product ions.