Determination of trichloroanisole and trichlorophenol in wineries’ ambient air by passive sampling and thermal desorption–gas chromatography coupled to tandem mass spectrometry

Targeted determination of volatile fluoroalkyl pollutants and non-targeted screening for environmental monitoring

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants known for their toxicity, mobility, and bioaccumulation. Efficient sample preparation and analysis of these compounds are critical for environmental monitoring. In this study, a novel analytical methodology is presented, integrating dynamic headspace extraction (DHS) and thermal desorption (TD) with one-dimensional (1D) and two-dimensional (2D) gas chromatography-time-of-flight mass spectrometry (GC-TOFMS) for the quantification of target volatile and semi-volatile PFAS. Such an approach also enables the non-targeted screening of other classes of contaminants in aqueous samples. The method was optimized and validated for nine (semi-)volatile PFAS, including fluorotelomer alcohols (FTOHs), acrylate (FTAc), and alkyl sulfonamides (FOSA, FOSE). Three types of adsorbent materials were evaluated during the enrichment step, among which Tenax TA demonstrated superior recovery and reproducibility. Extraction volumes of 1 L, 2 L, and 5 L were tested, with 1 L providing the most consistent recoveries and reproducibility. The optimized method achieved detection limits as low as 2.17 ng L-1, indicating high sensitivity. In a case study involving water from an industrial site, the enhanced separation and detection capabilities of GC×GC-TOFMS enabled the identification of 115 additional environmentally relevant compounds, including halogen-containing compounds, monoaromatics, and polycyclic aromatic hydrocarbons. This integrated DHS-TD-GC×GC-TOFMS approach provides a robust and suitable analytical solution for targeted PFAS monitoring, combining high sensitivity and selectivity with simultaneous non-targeted analytical capabilities - a particularly advantageous feature for the environmental monitoring of (semi-)volatile chemicals in real samples.

Effects of 2,4,6-Trichloroanisole on the morphological development and motility of zebrafish

2,4,6-Trichloroanisole (2,4,6-TCA), a compound with a characteristic earthy odor, is a common source of odorous pollutants in drinking water and wine. However, research on its biological toxicity is limited. In this study, we used zebrafish as an indicator model to investigate the effects of 2,4,6-TCA exposure on morphological development, oxidative stress, apoptosis, heart rate, blood flow, and motility. We found that exposure to 2,4,6-TCA resulted in significant spinal, tail, and cardiac deformities in zebrafish larvae and promoted a pronounced oxidative stress response and extensive cell apoptosis, notably in the digestive tract, head, spine, and heart, ultimately leading to significant reductions in zebrafish heart rate, blood flow, and motility. Moreover, these effects became more pronounced with an increase in the concentration of 2,4,6-TCA to which the zebrafish were exposed. Furthermore, qPCR analysis revealed that exposure to 2,4,6-TCA promoted significant changes in the expression levels of genes associated with oxidative stress, apoptosis, cardiac development, and the nervous system, particularly key genes (p53, apaf1, casp9, and casp3) in the mitochondrial apoptotic pathway, which were significantly upregulated. Similarly, we detected significant upregulation of ache gene expression. These findings indicated that exposure to 2,4,6-TCA resulted in the accumulation of reactive oxygen species in zebrafish, induced strong oxidative stress responses, and triggered lipid peroxidation and extensive cell apoptosis. Cellular apoptosis, which mitochondrial signaling pathways may mediate, has been found to lead to malformations in zebrafish embryos, resulting in significant reductions in cardiac function and motility. To our knowledge, this is the first systematic assessment of the toxicity of 2,4,6-TCA, and our findings provide an important reference for risk assessment and early warning of 2,4,6-TCA exposure.

Mold Odor from Wood Treated with Chlorophenols despite Mold Growth That Can Only Be Seen Using a Microscope

We previously reported that indoor odorous chloroanisoles (CAs) are still being emitted due to microbial methylation of hazardous chlorophenols (CPs) present in legacy wood preservatives. Meanwhile, Swedish researchers reported that this malodor, described since the early 1970s, is caused by hazardous mold. Here, we examined to what extent CP-treated wood contains mold and if mold correlates with perceived odor. We found no studies in PubMed or Web of Science addressing this question. Further, we investigated two schools built in the 1960s with odor originating from crawlspaces. No visible mold was evident in the crawlspaces or on the surfaces of treated wood samples. Using a microscope, varying amounts of mold growth were detected on the samples, all containing both CP(s) and CA(s). Some samples smelled, and the odor correlated with the amount of mold growth. We conclude that superficial microscopic mold on treated wood suffices produced the odor. Further, we argue that CPs rather than mold could explain the health effects reported in epidemiological studies that use mold odor as an indicator of hazardous exposure.

Assessment of air passive sampling uptakes for volatile organic compounds using VERAM devices

A calibration chamber has been designed and employed for the simple and easy determination of uptake sampling rate (R_S) of volatile organic compounds (VOCs) from air using passive samplers. A flow of clean air was continuously spiked, at a constant VOC concentration, by the microinjection of a standard solution by means of a T-type tube. The developed system allowed the complete evaporation at room temperature of the standard solution in acetone and the air concentration of VOCs was easily controlled by the regulation of the clean air flow, the standard solution concentration and its flow. Active sampling was employed for monitoring the true concentration of the evaluated compounds inside the calibration chamber, using Tenax-filled desorption tubes and a low flow personal air sampling pump. Versatile, easy and rapid atmospheric monitor (VERAM) devices were employed for the passive sampling of benzene, toluene, ethylbenzene, xylenes, α-pinene, camphene, myrcene, p-cymene, and limonene from air. The R_S values obtained for the passive sampling of VOCs, using the developed calibration chamber, were in the range of 1.3-16.0m³day^-1 in accordance to previous calibration studies performed for VERAM samplers. The developed calibration chamber provided a continuous flow with a constant concentration of the evaluated compounds that allowed the simultaneous deployment of several samplers for a rapid establishment of R_S for a passive sampler type and the easy comparison between different devices.

Headspace solid-phase microextraction coupled to gas chromatography-tandem mass spectrometry for the determination of haloanisoles in sparkling (cava and cider) and non-sparkling (wine) alcoholic beverages

A highly sensitive analytical method was developed to determine 2,4,6-trichloroanisole (TCA), 2,3,4,6-tetrachloroanisole (TeCA), 2,4,6-tribromoanisole (TBA) and 2,3,4,5,6-pentachloroanisole (PCA) in sparkling alcoholic beverages. The method was based on the use of headspace solid-phase microextraction (HS-SPME) using a polydimethylsiloxane (PDMS) fibre. It was coupled to gas chromatography-triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS) for the detection and quantification of the target haloanisoles. The method was fully automated and no sample preparation was needed. The method was validated for alcoholic beverages. The influence of CO₂ on the extraction efficiency was also evaluated for the studied sparkling drinks (cava and cider). All the calibration curves showed good linearity (R² > 0.98) within the tested range (1-50 ng l^-1). Recoveries were evaluated at three different levels (1, 5 and 50 ng l^-1) and were always between 71% and 119%. Precision was expressed as relative standard deviation (RSD), and was evaluated as intra- and inter-day precisions, with values ≤ 22% in both cases. Limits of quantitation (LOQs) were ≤ 0.91 ng l^-1, which are below the sensory threshold levels for such compounds in humans. The validated method was applied to commercial samples, 10 cavas and 10 ciders, but it was also used for the analysis of nine red wines and four white wines, demonstrating the further applicability of the proposed method to non-sparkling beverages. TCA was detected in most samples at up to 0.45 ng l^-1.