Comparison of Sample Preparation and Detection Methods for the Quantification of Synthetic Musk Compounds (SMCs) in Carp Fish Samples.

This study deals with the separation and detection methods for 12 synthetic musk compounds (SMCs), which are some of the emerging contaminants in fish samples, are widely present in environmental media, and can be considered serious risks due to their harmful effects. For the separation of co-extracted substances and the target SMCs in fish samples after ultrasonic extraction, four solid-phase extraction (SPE) sorbents were investigated. The recoveries of SMCs from 10 mL of eluent, as optimized by the elution profile, were within the acceptable range of 80-120% in all SPE types, and it was found that nitro musk and polycyclic musk compounds were separated more clearly in Florisil SPE than others (Aminopropyl, Alumina-N, PSA).

Statistical comparison for assessing agreement between two mass spectrometric methods for the analysis of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs) in contaminated soils.

A gas chromatography coupled to high-resolution mass spectrometry (GC-HR/MS) has been used as the standard method for the quantification of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs), which are regulated at screening and action levels in the environment. However, several alternative methods have been attempted due to the disadvantage of its high cost. Although a gas chromatography with triple quadrupole mass spectrometry (GC-QqQ-MS/MS) has been used in a wide variety of sample matrices, showing that they are interchangeable, there has been a lack of comprehensive studies on statistical agreement with GC-HR/MS.

Ultrasonic treatment of endocrine disrupting compounds, pharmaceuticals, and personal care products in water: An updated review.

Pharmaceuticals, personal care products (PPCPs), and endocrine-disrupting compounds (EDCs) have seen a recent sustained increase in usage, leading to increasing discharge and accumulation in wastewater. Conventional water treatment and disinfection processes are somewhat limited in effectively addressing this micropollutant issue. Ultrasonication (US), which serves as an advanced oxidation process, is based on the principle of ultrasound irradiation, exposing water to high-frequency waves, inducing thermal decomposition of HO while using the produced radicals to oxidize and break down dissolved contaminants.

Improvement of the anthropogenic emission rate estimate in Ulaanbaatar, Mongolia, for 2020-21 winter.

Ulaanbaatar (UB), the fast-growing capital of Mongolia, is known for its world's worst level of particulate matter (PM) concentrations in winter. However, current anthropogenic emission inventories over the UB are based on data from more than fifteen years ago, and satellite observations are scarce because UB is in high latitudes. During the winter of 2020-21, the first period of the Fine Particle Research Initiative in East Asia considering the National Differences (FRIEND), several times higher concentrations of PM in UB compared to other urban sites in East Asia were observed but not reproduced with a chemical transport model mainly due to the underestimated anthropogenic emissions.

Implications of PM chemical composition in modulating microbial community dynamics during spring in Seoul.

Particulate matter with an aerodynamic diameter of 2.5 μm or less (PM) harbors a diverse microbial community. To assess the ecological dynamics and potential health risks associated with airborne microorganisms, it is crucial to understand the factors influencing microbial communities within PM.

Effects of volatile organic compounds and new particle formation on real-time hygroscopicity of PM particles in Seosan, Republic of Korea.

The hygroscopicity of PM particles plays an important role in PM haze in Northeast Asian countries by influencing particle growth and chemical composition. New particle formation (NPF) and atmospheric volatile organic compounds (VOCs) are factors that influence particle hygroscopicity. However, the lack of real-time hygroscopicity measurements has deterred the understanding of their effects on particle hygroscopicity.

When and why PM is high in Seoul, South Korea: Interpreting long-term (2015-2021) ground observations using machine learning and a chemical transport model.

Seoul has high PM concentrations and has not attained the national annual average standard so far. To understand the reasons, we analyzed long-term (2015-2021) hourly observations of aerosols (PM, NO, NH, SO, OC, and EC) and gases (CO, NO, and SO) from Seoul and Baekryeong Island, a background site in the upwind region of Seoul. We applied the weather normalization method for meteorological conditions and a 3-dimensional chemical transport model, GEOS-Chem, to identify the effect of policy implementation and aerosol formation mechanisms.

Impact of ozonation on the formation of particulate nitrosodi-methylamine (NDMA) in atmosphere.

The contribution of ozonation to the formation of particulate nitrosodi-methylamine (NDMA) in the aqueous aerosol phase was investigated using measurement data from 2018 in Seoul, Republic of Korea and a box model. The correlation between the NDMA concentration and aerosol liquid water content and box model results showed that aqueous aerosol phase reactions, including nitrosation and ozonation, might contribute to the formation of NDMA. The concentration of NDMA and the ratio of O/dimethylamine exhibited a negative correlation, suggesting that the contribution of ozonation to NDMA formation may not be significant.

Molecular-level chemical composition of aerosol and its potential source tracking at Antarctic Peninsula.

Marine organic aerosols play crucial roles in global climatic systems. However, their chemical properties and relationships with various potential organic sources still need clarification. This study employed high-resolution mass spectrometry to investigate the identity, origin, and transportation of organic aerosols in pristine Antarctic environments (King Sejong Station; 62.

Developing an Improved Strategy for the Analysis of Polychlorinated Dibenzo-p-Dioxins/Furans and Dioxin-like Polychlorinated Biphenyls in Contaminated Soils Using a Combination of a One-Step Cleanup Method and Gas Chromatography with Triple Quadrupole Mass Spectrometry.

Soils contaminated with polychlorodibenzo-p-dioxins (PCDDs), polychlorodibenzofurans (PCDFs), and dioxin-like (dl) polychlorinated biphenyls (PCBs), known as persistent organic pollutants (POPs), have garnered global attention because of their toxicity and persistence in the environment. The standard method for target analytes has been used; however, it is an obstacle in large-scale sample analysis due to the comprehensive sample preparation and high-cost instrumental analysis. Thus, analytical development of inexpensive methods with lower barriers to determine PCDDs/Fs and dl-PCBs in soil is needed.

Comparative analysis of organic chemical compositions in airborne particulate matter from Ulaanbaatar, Beijing, and Seoul using UPLC-FT-ICR-MS and artificial neural network.

This paper presents comparative study on the composition and sources of PM in Ulaanbaatar, Beijing, and Seoul. Ultrahigh performance liquid chromatography (UPLC) combined with ultrahigh resolution mass spectrometry (UHR-MS) were employed to analyze 85 samples collected in winter. The obtained 340 spectra were interpreted with artificial neural network (ANN).

Parameterization of below-cloud scavenging for polydisperse fine mode aerosols as a function of rain intensity.

The below-cloud aerosol scavenging process by precipitation is one of the most important mechanisms to remove aerosols from the atmosphere. Due to its complexity and dependence on both aerosol and raindrop sizes, wet scavenging process has been poorly treated, especially during the removal of fine particles. This makes the numerical simulation of below-cloud scavenging in large-scale aerosol models unrealistic.

Ocean-atmosphere interactions: Different organic components across Pacific and Southern Oceans.

Sea spray aerosol (SSA) particles strongly influence clouds and climate but the potential impact of ocean microbiota on SSA fluxes is still a matter of active research. Here-by means of in situ ship-borne measurements-we explore simultaneously molecular-level chemical properties of organic matter (OM) in oceans, sea ice, and the ambient PM aerosols along a transect of 15,000 km from the western Pacific Ocean (36°13'N) to the Southern Ocean (75°15'S). By means of orbitrap mass spectrometry and optical characteristics, lignin-like material (24 ± 5 %) and humic material (57 ± 8 %) were found to dominate the pelagic Pacific Ocean surface, while intermediate conditions were observed in the Pacific-Southern Ocean waters.

Development of Quantitative Chemical Ionization Using Gas Chromatography/Mass Spectrometry and Gas Chromatography/Tandem Mass Spectrometry for Ambient Nitro- and Oxy-PAHs and Its Applications.

The concentration of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere has been continually monitored since their toxicity became known, whereas nitro-PAHs (NPAHs) and oxy-PAHs (OPAHs), which are derivatives of PAHs by primary emissions or secondary formations in the atmosphere, have gained attention more recently. In this study, a method for the quantification of 18 NPAH and OPAH congeners in the atmosphere based on combined applications of gas chromatography coupled with chemical ionization mass spectrometry is presented. A high sensitivity and selectivity for the quantification of individual NPAH and OPAH congeners without sample preparations from the extract of aerosol samples were achieved using negative chemical ionization (NCI/MS) or positive chemical ionization tandem mass spectrometry (PCI-MS/MS).

Comparison of Phase States of PM over Megacities, Seoul and Beijing, and Their Implications on Particle Size Distribution.

Although the particle phase state is an important property, there is scant information on it, especially, for real-world aerosols. To explore the phase state of fine mode aerosols (PM) in two megacities, Seoul and Beijing, we collected PM filter samples daily from Dec 2020 to Jan 2021. Using optical microscopy combined with the poke-and-flow technique, the phase states of the bulk of PM as a function of relative humidity (RH) were determined and compared to the ambient RH ranges in the two cities.

Gas chromatography-triple quadrupole mass spectrometry as a cost-effective method for the determination of polychlorinated dibenzo-p-dioxins and furans in contaminated soils.

The aim of this study was to evaluate the performance of gas chromatography (GC)-triple quadrupole mass spectrometry (QqQ, MS/MS) as an alternative to the standard GC-high resolution mass spectrometry (GC-HR/MS) for soils contaminated with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). GC-QqQ (MS/MS) using a dynamic multiple reaction monitoring (dMRM) mode was optimized for the quantitative analysis of 17 PCDD/Fs. A comparative study between GC-QqQ (MS/MS) and GC-HR/MS was carried out to validate the results of actual field soil samples.

Characteristics of volatile organic compounds in the metropolitan city of Seoul, South Korea: Diurnal variation, source identification, secondary formation of organic aerosol, and health risk.

Atmospheric volatile organic compounds (VOCs) in Seoul, the capital of South Korea, have attracted increased attention owing to their emission, secondary formation, and human health risk. In this study, we collected 24 hourly samples once a month at an urban site in Seoul for a year (a total of 288 samples) using a sequential tube sampler. Analysis results revealed that toluene (9.

Contribution of liquid water content enhancing aqueous phase reaction forming ambient particulate nitrosamines.

Contribution of liquid water content (LWC) to the levels of the carcinogenic particulate nitro(so) compounds and the chemistry affecting LWC were investigated based on the observation of seven nitrosamines and two nitramines in rural (Seosan) and urban (Seoul) area in South Korea during October 2019 and a model simulation. The concentrations of both the total nitrosamines and nitramines were higher in Seosan (12.48 ± 16.

Spatial Association of Urban Form and Particulate Matter.

Increasingly detrimental effects of fine particulate matter (PM) have been observed in Northeast Asia owing to its rapid economic development. Previous studies have found that dust, combustion, and chemical reactions are the major sources of PM; nevertheless, the spatial configuration of land use and land cover, which is of most interest to planners and landscape architects, also influences the PM levels. Here, we attempted to unveil the relationship between PM and different types of land use cover (i.

Particulate Nitrosamines and Nitramines in Seoul and Their Major Sources: Primary Emission versus Secondary Formation.

Seven nitrosamines and three nitramines in particulate matter with an aerodynamic diameter of less than or equal to 2.5 μm (PM) collected in 2018 in Seoul, South Korea, were quantified. Annual mean concentrations of the sum of nitrosamines and nitramines were 9.

Trace Level Determination of Saccharides in Pristine Marine Aerosols by Gas Chromatography-Tandem Mass Spectrometry.

The quantification and identification of saccharides in pristine marine aerosols can provide useful information for determining the contributions of anthropogenic and natural sources of the aerosol. However, individual saccharide compounds in pristine marine aerosols that exist in trace amounts are difficult to analyze due to their low concentrations. Thus, in this study, we applied gas chromatography-tandem mass spectrometry (GC-MS/MS) in multiple reaction monitoring (MRM) mode to analyze the particulate matter with an aerodynamic diameter equal or less than 2.

Determination of atmospheric amines at Seoul, South Korea via gas chromatography/tandem mass spectrometry.

Due to their important roles in salt-producing acid-base reactions, new particle formation (NPF), and as precursors in secondary organic aerosol (SOA) producing reactions, the atmospheric concentrations of particulate volatile amines (dimethylamine (DMA), ethylamine, diethylamine (DEA), propylamine, and butylamine) at Seoul were analyzed and evaluated. To quantify the presence of volatile amines in particulate matter with aerodynamic diameters less than or equal to a nominal 2.5 μm (PM), an efficient and rapid analytical method based on in-matrix ethyl chloroformate (ECF) derivatization followed by headspace solid-phase microextraction (HS-SPME) was developed and validated using gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) in the multiple reaction monitoring (MRM) mode.

Oxygenated polycyclic aromatic hydrocarbons from ambient particulate matter induce electrophysiological instability in cardiomyocytes.

Background: Epidemiologic studies have suggested that elevated concentrations of particulate matter (PM) are strongly associated with an increased risk of developing cardiovascular diseases, including arrhythmia. However, the cellular and molecular mechanisms by which PM exposure causes arrhythmia and the component that is mainly responsible for this adverse effect remains to be established. In this study, the arrhythmogenicity of mobilized organic matter from two different types of PM collected during summer (SPM) and winter (WPM) seasons in the Seoul metropolitan area was evaluated.

Recent Occurrence of PAHs and n-Alkanes in PM2.5 in Seoul, Korea and Characteristics of their Sources and Toxicity.

Polycyclic Aromatic Hydrocarbons (PAHs) and n-alkanes in particulate matter with an aerodynamic diameter of 2.5 micrometers or less (PM2.5) were quantified at Seoul, Korea in 2018.