Environmental analysis of polar and non-polar Polycyclic Aromatic Compounds in airborne particulate matter, settled dust and soot: Part I: Sampling and sample preparation

An Integrated Workflow Assisted by In Silico Predictions To Expand the List of Priority Polycyclic Aromatic Compounds

The limited information in existing mass spectral libraries hinders an accurate understanding of the composition, behavior, and toxicity of organic pollutants. In this study, a total of 350 polycyclic aromatic compounds (PACs) in 9 categories were successfully identified in fine particulate matter by gas chromatography high resolution mass spectrometry. Using mass spectra and retention indexes predicted by in silico tools as complementary information, the scope of chemical identification was efficiently expanded by 27%. In addition, quantitative structure-activity relationship models provided toxicity data for over 70% of PACs, facilitating a comprehensive health risk assessment. On the basis of extensive identification, the cumulative noncarcinogenic risk of PACs warranted attention. Meanwhile, the carcinogenic risk of 53 individual analogues was noteworthy. These findings suggest that there is a pressing need for an updated list of priority PACs for routine monitoring and toxicological research since legacy polycyclic aromatic hydrocarbons (PAHs) contributed modestly to the overall abundance (18%) and carcinogenic risk (8%). A toxicological priority index approach was applied for relative chemical ranking considering the environmental occurrence, fate, toxicity, and analytical availability. A list of 39 priority analogues was compiled, which predominantly consisted of high-molecular-weight PAHs and alkyl derivatives. These priority PACs further enhanced source interpretation, and the highest carcinogenic risk was attributed to coal combustion.

Airborne Pesticides-Deep Diving into Sampling and Analysis

The escalating utilization of pesticides has led to pronounced environmental contamination, posing a significant threat to agroecosystems. The extensive and persistent global application of these chemicals has been linked to a spectrum of acute and chronic human health concerns. This review paper focuses on the concentrations of airborne pesticides in both indoor and outdoor environments. The collection of diverse pesticide compounds from the atmosphere is examined, with a particular emphasis on active and passive air sampling techniques. Furthermore, a critical evaluation is conducted on the methodologies employed for the extraction and subsequent quantification of airborne pesticides. This analysis takes into consideration the complexities involved in ensuring accurate measurements, highlighting the advancements and limitations of current practices. By synthesizing these aspects, this review aims to foster a more comprehensive and informed comprehension of the intricate dynamics related to the presence and measurement of airborne pesticides. This, in turn, is poised to significantly contribute to the refinement of environmental monitoring strategies and the augmentation of precise risk assessments.

Development and validation of an improved QuEChERS method for the extraction of semi-volatile organic compounds (SVOCs) from complex soils

In order to achieve rapid, sensitive, and high-throughput determination of typical semi-volatile organic compounds (SVOCs) in soil samples, a method for the rapid determination of 63 SVOCs in soil was developed by optimizing and improving the QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction technique in conjunction with gas chromatography-mass spectrometry (GC-MS) analysis. A small amount of soil sample (5.0 g) was vortexed with 10 mL of a mixture of acetone and n-hexane (V/V = 1 : 1) for 2 min, followed by rapid vortex purification and centrifugation using a mixture of copper powder and octadecylsilane (C18) dispersant. The resulting supernatant was then purified through a 0.22 μm filter membrane. The results showed that the 63 SVOCs exhibited good linear relationships within the concentration range of 100-5000 μg L-1, with correlation coefficients (R2) above 0.99. The method detection limit (MDL = 3.3 Sy/m) was lower than 0.050 mg kg-1. At a spike concentration of 1 mg kg-1, the recovery rates of the 63 SVOCs were almost above 70% (n = 7). Compared with the rapid solvent extraction (ASE) method specified in US EPA 3545 standard, this method reduced the organic solvent usage by 14 times and significantly shortened the operation time. Furthermore, this method did not involve any transfer or concentration steps of the extractant during the experimental process, reducing the exposure time of toxic compounds and providing support for the principles of green analytical chemistry. Moreover, in the detection of most compounds in the same batch of contaminated soil, the extraction results obtained by QuEChERS were superior to those obtained by the ASE method, providing evidence for the practical application of this method. This method is rapid, simple, accurate, requires a small sample volume, and causes minimal environmental pollution. It provides a high-throughput detection method for the rapid screening of SVOCs in soil.

Analysis of Polycyclic Aromatic Hydrocarbon in Airborne Particulate Matter Samples by Gas Chromatography in Combination with Tandem Mass Spectrometry (GC-MS/MS)

Polycyclic aromatic hydrocarbons (PAHs), the family of organic contaminations, have been shown to have negative effects on human health. However, until now, the comprehension on occurrence, distribution, and risk assessment of human exposure to PAHs has been limited in Vietnam. In this work, a capillary gas chromatography coupled with electron impact ionization tandem mass spectrometry (GC-EI-MS/MS) has been introduced for analysis of 16 PAHs in some particulate matter samples. PAHs have been separated on the TG 5 ms capillary gas chromatographic column and detected by tandem mass spectrometry in multiple reaction monitoring mode. The PAHs in the particulate matter (PM 2.5 and PM 10) samples were extracted by ultrasonic-assisted liquid extraction and cleaned up by an acidic silica gel solid phase extraction. The linearity range of all analyzed PAHs was from 5 to 2000 ng mL^-1 with R ² ≥0.9990. Limit of detection (LOD) of PAHs in particulate matter sample was from 0.001 ng m^-3 (Br-Naph) to 0.276 ng m^-3 (Fln). The recovery of PAHs was investigated by international proficiency testing samples. The recoveries of PAHs in proficiency testing sample ranged from 79.3% (Chr) to 109.8% (IcdP). The in-house validated GC-EI-MS/MS method was then applied to analysis of some particulate matter samples that were collected in the Hanoi areas. The total concentrations of PAHs in several brands of samples collected from Hanoi were found in the range of 226.3 ng m^-3-706.43 ng m^-3. Among the studied compounds, naphthalene was found at high frequency and ranged from 106.5 ng m^-3 to 631.1 ng m^-3. The main distribution of the PAHs in particulate matter samples was two-ring and three-ring compounds.