Seasonal variation in characteristics of wear microparticles of high density (> 1.8 g cm) produced on road.

Wear microparticles are produced on roads by traffic, and they can be transferred to rivers and seas settling as sediments. The sedimentation rate increases with increasing particle density and size. In this study, the types and amounts of high-density wear microparticles (HDWPs, >1.

An on-site inspection system for explosives in a container using dust collection through a vent cover and ion mobility spectrometric detection.

Rapid and accurate cargo-inspection systems are required for shipping containers, because illegal and hazardous items, such as explosives and drugs, can be easily concealed in large containers. Dust in a container is suspended in the air and deposited in vent covers. The vapor and particulate matter of explosives can be adsorbed onto the dust.

Abrasion Behaviors of Silica-Reinforced Solution Styrene-Butadiene Rubber Compounds Using Different Abrasion Testers.

Solution styrene-butadiene rubber (SSBR) is widely used to improve the properties of tire tread compounds. Tire wear particles (TWPs), which are generated on real roads as vehicles traverse, represent one of significant sources of microplastics. In this study, four SSBR compounds were prepared using two SSBRs with high styrene (STY samples) and 1,2-unit (VIN samples) contents, along with dicyclopentadiene resin.

Characteristics of tire-road wear particles (TRWPs) and road pavement wear particles (RPWPs) generated through a novel tire abrasion simulator based on real road pavement conditions.

Microparticles such as tire-road wear particles (TRWPs) and road pavement wear particles (RPWPs) are generated by the friction between tire tread and road surface. TRWPs and RPWPs on roads are dispersed through traffic and transferred to rivers and seas via runoff to accumulate in sediments. However, research on the generation of both TRWP and RPWP has rarely been conducted.

Types and concentrations of tire wear particles (TWPs) in road dust generated in slow lanes.

Drivers commonly navigate their vehicles at moderate speeds in proximity to traffic lights. In this study, road dust samples were collected in the vicinity of traffic lights, as well as at a taxi stand (TS) situated between traffic lights, with considerations given to both forward direction (FD) and backward direction (BD). The characterization of tire wear particles (TWPs) in the road dust was meticulously conducted based on particle size.

Characteristics of particulate matter from asphalt pavement and tire of a moving bus through driving tests in city road and proving ground.

Non-exhaust PM emissions from vehicles in real road have been conducted, but heavy vehicles have rarely been tested. In this study, PM and PM samples were directly collected from a tire of a moving bus and the composition was analyzed to investigate the sources of PM emissions. Driving tests were conducted at a proving ground (PG) and a city road (CR).

Concentrations of particulate matter (PM) and contributions of tire wear particle to PM in an indoor parking garage: Comparison with the outside and the differences according to the sampling sites.

Particulate matter (PM) is increasingly affecting the social-economic development of countries. An increase in PM concentration increases susceptibility to cardiovascular and respiratory diseases and cancer. Tire wear particles (TWP) contribute to airborne PM.

Ionization behaviors of nitrotoluenes and dinitrotoluenes by reactions with acetone-related reactant ion.

Dinitrotoluenes (DNTs) and nitrotoluenes (NTs) are found in the environment as metabolites of trinitrotoluene (TNT). When acetone is used as the solvent/eluent in atmospheric pressure chemical ionization-mass spectrometry (APCI-MS), the reactant ion is [2Acetone + O ] for the negative ion mode. The reactant ion reacts with an analyte to produce M and/or [M - H] under atmospheric pressure.

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.

Quantification of tire tread wear particle in road dust through pyrolytic technique.

Road dust cotains tire wear particles (TWPs) and a large amount of mineral particles (MPs). Given that tire tread in vehicles is mainly comprised of natural rubber (NR), isoprene and dipentene could be the main pyrogenic products stemmed from the thermolysis of NR. This offers a great chance to quantify the exact mass of TWP in road dust.

Comparison of polymeric components and tire wear particle contents in particulate matter collected at bus stop and college campus.

Particulate matter (PM) samples were collected at two different places of a college campus (CC) and a bus stop (BS) nearby the college campus. The traffic volume of college campus was very low due to untact classes. Polymeric components and tire wear particle (TWP) contents in the PM samples were analyzed using pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS).

Variation in Abundance Ratio of Isoprene and Dipentene Produced from Wear Particles Composed of Natural Rubber by Pyrolysis Depending on the Particle Size and Thermal Aging.

Tire wear particles (TWPs) are generated by friction between the road and the tire. TWPs are one of the major microplastics found in environmental samples, such as road dust, particulate matter (PM), and sediment. TWP contents in environmental samples are generally analyzed using the pyrolysis technique.

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.

Analysis of Polymeric Components in Particulate Matter Using Pyrolysis-Gas Chromatography/Mass Spectrometry.

Particulate matters (PMs) such as PM and PM were collected at a bus stop and were analyzed using pyrolysis-gas chromatography/mass spectrometry to identify organic polymeric materials in them. The major pyrolysis products of the PM samples were isoprene, toluene, styrene, dipentene, and 1-alkenes. The pyrolysis products generated from the PM samples were identified using reference polymeric samples such as common rubbers (natural rubber, butadiene rubber, and styrene-butadiene rubber), common plastics (polyethylene, polypropylene, polystyrene, and poly(ethylene terephthalate)), plant-related components (bark, wood, and leaf), and bitumen.

Characteristics of ionization behaviors of aminonitrotoluene isomers produced by atmospheric pressure chemical ionization.

Rationale: Six of the isomers of aminonitrotoluene (ANT) are 2-amino-3-nitrotoluene (2A3NT), 2A4NT, 2A5NT, 2A6NT, 4A2NT, and 4A3NT. Some of them can be identified by chromatography and spectroscopy. Biochemical transformation of 2,4,6-trinitrotoluene (TNT) and dinitrotoluenes (DNTs) is very complex and ANTs are decomposition products of TNT and DNTs.

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.

Classification and Characterization of Tire-Road Wear Particles in Road Dust by Density.

Tire treads are abraded by friction with the road surface, producing tire tread wear particles (TWPs). TWPs combined with other particles on the road such as road wear particles (RWPs) and mineral particles (MPs), forming tire-road wear particles (TRWPs). Dust on an asphalt pavement road is composed of various components such as TRWPs, asphalt pavement wear particles (APWPs), MPs, plant-related particles (PRPs), and so on.

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.

Quantification of tire tread wear particles in microparticles produced on the road using oleamide as a novel marker.

In general, tire tread rubber compounds contain oleamide for improvement of manufacturing processibility, mold release characterization, and abrasion resistance. Tire tread wear particles (TWPs) are one of major contributors to microplastic emissions. In this study, a novel analytical method for quantification of TWP in microparticles produced on the road (road dust, MPRs) was developed by employing oleamide as a new marker.

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).

Characterization of the fragmentation behaviors of protonated α-cyclodextrin generated by electrospray ionization.

Rationale: Electrospray ionization (ESI) of an aqueous solution of α-cyclodextrin (α-CD) gave a protonated molecule, [α-CD + H] . The fragmentation behavior of the protonated molecule, including direct decomposition and ring cleavage, was investigated by varying the source fragmentor voltage. The possible chemical structures of the product ions were also examined using electronic structure calculations.

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.

Formation of deaminated dimer species of amino acids by atmospheric pressure chemical ionization.

Rationale: Interactions of biological molecules to form cluster species play a key role in biological processes and investigation of non-covalent complexes is one of the research fields using mass spectrometry. Atmospheric pressure chemical ionization mass spectrometry (APCI-MS) is a useful method for the investigation of cluster formation of amino acids (AAs) by ion-molecule reactions.

Methods: A mixture of 20 protein AAs was ionized by APCI and the product ions were analyzed.

Novel co-matrix systems for the MALDI-MS analysis of polystyrene using a UV absorber and stabilizer.

Co-matrix systems composed of a UV absorber and a UV stabilizer applied to the analysis of polystyrene (PS) using a matrix-assisted laser desorption/ionization-mass spectrometer (MALDI-MS) equipped with a N(2) laser (337 nm) as the light source were investigated. Various UV absorbers such as Tinuvin 234, Tinuvin 326, Tinuvin 327, Tinuvin 328, Tinuvin 329, and Tinuvin 1577 and a UV stabilizer of Tinuvin 770 were used. Analytical results using the co-matrix systems were compared with those using anthracene-1,8,9-triol (DIT) as the most common matrix for PS analysis.