Test method for vapor collection and ion mobility detection of explosives with low vapor pressure.

Rationale: Ion mobility spectrometry (IMS) has been widely used for on-site detection of explosives. Air sampling method is applicable only when the concentration of explosive vapor is considerably high in the air, but vapor pressures of common explosives such as 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX), and pentaerythritol tetranitrate (PETN) are very low. A test method for analyzing the vapor detection efficiency of explosives with low vapor pressure via IMS was developed using artificial vapor and collection matrices.

Deprotonation of trinitrotoluene by dichloromethane in atmospheric pressure chemical ionization mass spectrometry.

Rationale: Trinitrotoluene (TNT) and its derivatives are found in the environment. Depending on the analysis conditions, TNT may be detected as a deprotonated molecule or a molecular ion through atmospheric pressure chemical ionization (APCI). Dichloromethane (CH Cl ) is used as an extraction solvent for TNT from environmental samples and as an ionizing agent to generate chlorinated species.

Preparation and Characterization of Model Tire-Road Wear Particles.

Tire tread wear particles (TWPs) are one of major sources of microplastics in the environment. Tire-road wear particles (TRWPs) are mainly composed of TWPs and mineral particles (MPs), and many have long shapes. In the present work, a preparation method of model TRWPs similar to those found in the environment was developed.

Complex formation of lactic acid by atmospheric pressure chemical ionization.

Oligomers and polymers of lactic acid are generally synthesized through condensation reactions by dehydration at high emperature under catalysis. In the present work, ionization behaviors of lactic acid produced by atmospheric pressure chemical ionization were investigated. Influence of the sample concentration, the heating zone temperature, and the source fragmentor voltage on kinds and abundances of the product ions was examined.

Direct detection of diphenylamino radical formed by oxidation of diphenylamine using atmospheric pressure chemical ionization mass spectrometry.

Rationale: Diphenylamine (DPAH) and its derivatives have been widely used as antioxidants. Its antioxidation behaviors are started with the formation of diphenylamino radical (DPA ) by loss of hydrogen atom through reaction with oxygen or ozone. DPAH was oxidized by ozonation to produce DPA and DPA was directly detected using atmospheric pressure chemical ionization mass spectrometry (APCI-MS).

The influence of different types of reactant ions on the ionization behavior of polycyclic aromatic hydrocarbons in corona discharge ion mobility spectrometry.

Rationale: Some polycyclic aromatic hydrocarbons (PAHs) are considered to be cancer-causing chemicals, and ion mobility spectrometry (IMS) is used for on-site detection of such hazardous chemicals. In IMS, the ionization behavior of analytes is affected by the types of reactant ions (RIs). In the present work, the influence of different types of RIs on the ionization behaviors of PAHs in an ion mobility spectrometer equipped with a corona discharge ionization source was investigated using various RIs.

Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons using ion mobility spectrometry.

Influence of smear matrix types on detection behaviors and efficiencies of polycyclic aromatic hydrocarbons (PAHs) with different molecular weights in ion mobility spectrometry (IMS) were investigated. Various smear matrices of stainless steel mesh (SM), cellulose paper (CP), and cotton fabric (CF) were employed. Anisole was used as the solvent and IMS analysis was performed without evaporation step of the solvent to apply charge transfer reactions between PAH molecules and the molecular ions of solvent.