Phthalic Acid Esters Research Articles

Development and validation of a GC Orbitrap-MS method for the analysis of phthalate esters (PAE) and bis(2-ethylhexyl)adipate (DEHA) in atmospheric particles and its application for screening PM2.5 from Curitiba, Brazil.

Phthalates or phthalic acid esters (PAE) and bis(2-ethylhexyl)adipate (DEHA) are ubiquitous chemicals often used as plasticisers and additives in many industrial products and are classified as both persistent organic pollutants (POPs) and new emerging pollutants (NEPs). Exposure to these chemicals, especially through inhalation, is linked to a wide range of negative health effects, including endocrine disruption. Air particulate matter (PM) with an aerodynamic diameter ≤ 2.5 μm can be enriched with PAEs and DEHA and if inhaled can cause multi-system human toxicity. Therefore, proper monitoring of PAEs and DEHA in PM is required to assess human exposure to these pollutants. In this work, we developed and validated a new and sensitive gas-chromatography high-resolution mass spectrometry (GC-HRMS) method for targeted analysis of PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), benzyl butyl phthalate (BBP), bis(2-ethylhexyl)adipate (DEHA), bis(2-ethylhexyl)phthalate (DEHP), di-n-octyl phthalate (DOP), in PM. Analytical aspects including sample preparation steps and GC-HRMS parameters, e.g., quadrupole isolation window, to enhance method sensitivity have been assessed. The estimated limit of detection (LODs) of target PAEs and DEHA ranged from 5.5 to 17 pg μL-1, allowing their trace-level detection in PM. Extraction efficiencies of 78-101% were obtained for the target compounds. Low DMP and DEP extraction efficiencies from the spiked filter substrates indicated that significant losses of higher volatility PAEs can occur during the sample collection when filter-based techniques are used. This work is the first targeted method based on GC-Orbitrap MS for PAEs and DEHA in environmental samples. The validated method was successfully applied for the targeted analysis of PAEs and DEHA in PM2.5 samples from the eighth most populous city in Brazil, Curitiba. This work is the first to report DBP, DEHA, DEHP, and DOP in urban PM from Brazil. The observed concentrations of PAEs (up to 29 ng m-3) in PM2.5 from Curitiba may not represent the extent of pollution by these toxic compounds since the analysed samples were collected during a COVID-19 restriction when anthropogenic activities were reduced.

EVALUATION OF THE THERMAL-OXIDATIVE STABILITY OF A HALOGEN-CONTAINING PLASTICIZER-FIRE RETARDANT

The importance of assessing the indicators of thermal-oxidative stability of plasticizers that are part of polymer compositions for ensuring high performance indicators during their processing and operation of finished products is noted. When using brominated organic compounds of the aromatic series, a short burning time of polymer compositions and a significant smoldering time have been established. The use of flame retardants containing a halogen in the aliphatic radical leads to a decrease in the smoldering time and an increase in the duration of combustion due to a decrease in the thermal stability of the material at the stage of decomposition. It is indicated that bromine-containing compounds give the best inhibition effect compared to chlorine-containing compounds due to a decrease in the carbon-bromine bond breaking energy compared to the carbon-chlorine bond energy. The decomposition parameters of the brominated plasticizer-fire retardant have been established. It is shown that the thermal decomposition of the brominated plasticizer occurs in two stages, corresponding to the elimination of bromine from the aliphatic radical in the temperature range 473 K – 573 K and the decomposition of phthalic acid esters in the range 603 K – 623 K. The beginning of intensive decomposition corresponds to 443 K. The maximum of the first stage of decomposition is at the point corresponding to 501 K, the second - 606-623 K. It was noted that the bromine-free plasticizer decomposes intensively, starting from 503 K and reaches the maximum decomposition rate at 611 K. The maximum loss of the bromine-free plasticizer was established at 27%, brominated - 50.9% of the mass of the sample. It has been confirmed that the presence of bromine atoms in the plasticizer adversely affects its thermal stability. The influence of the degree of halogenation of an unsaturated plasticizer on the nature of its thermal-oxidative degradation in the temperature range corresponding to the technological parameters of processing polymeric materials at elevated temperatures of 413-443 K has been studied. It is shown that an increase in the content of bromine in the plasticizer when performing technological operations for the processing of polymer compositions in the specified temperature range and the duration of exposure to elevated temperatures within one hour does not significantly affect the mass fraction of bromine in the plasticizer. A kinetic equation for the reaction of thermal decomposition of a bromine-containing plasticizer-flame retardant of the phthalate type, accompanied by the elimination of hydrogen bromide, is proposed. The activation parameters of the hydrogen bromide evolution reaction were determined for the temperature range of maximum decomposition of a brominated phthalate plasticizer with a bromine content in the range of 5% – 25%. It is shown that the activation energy of hydrogen bromide elimination depends on the bromine content in the plasticizer and decreases by 23% with an increase in the degree of bromination. It is shown that the temperature range of maximum decomposition of the brominated fire retardant plasticizer, corresponding to 473 K – 573 K, allows using it as a secondary plasticizer for polyvinyl chloride without reducing the thermal stability of the base.

Exposure risk assessment of representative phthalate acid esters and associated plastic debris under the agricultural land use in typical Chinese regions

Phthalate acid esters (PAEs) are frequently detected in the global environment and can cause potential health hazards. In this study, quantitative exposure risk assessment was undertaken to derive soil generic assessment criteria (GAC) for six representative PAEs under the agricultural land use in the evaluated Chinese regions, which coupled multi-media transport and human exposure models based on multiple exposure pathways including vegetables consumption, dermal absorption, ingestion of soil and dust, and the exposure from non-soil sources. It is identified that the PAEs in agricultural soil are dominated by DEHP and DnBP representing 72–96% of the total PAEs. The GAC for BBP and DEHP, calculated on the basis of region-specific exposure parameters and soil properties in various locations, are stringent, signifying greater potential health risks from exposure to them, warranting more rigorous contamination management. The proposed soil GAC for plastic debris are 100, 107, 73 and 88 mg kg−1 for Heilongjiang Province, Beijing City, Jiangsu and Guangdong Provinces respectively. Additionally, the potential risks of 1.68 × 10−6 and 7 × 10−6 are identified for BBP and DEHP in Guangdong Province as indicated by the exceedance of target risk level of 1 × 10−6, with the consumption of vegetables being the dominant contributor to the total estimated PAEs exposure. Overall, this methodology based on the coupled contaminant transport and exposure models incorporating region-specific data provides a technical framework to derive science-based soil GAC for representative PAEs for maintaining and assessing soil quality and food safety under the agricultural land use.

Fast and reliable determination of phthalic acid esters in soil and lettuce samples based on QuEChERS GC–MS/MS

Phthalates are commonly used as plasticizers, and solvents in industry and households. We propose an application of the QuEChERS method for the determination of six PAEs in the soil and lettuce (roots and leaves) by GC–MS/MS. The QuEChERS method validation procedure was performed and good linearity (>0.997), recovery (97.2–99.1 %), very low detection limits (0.09–0.43 ng/g), and satisfactory inter- and intraday precision (∼4%) were obtained confirming that QuEChERS GC–MS/MS applied for PAEs determination in the environmental samples is a cheap and environmentally friendly method. In general, the higher the number of carbon atoms in PAEs, the higher the percentage noted in the lettuce roots. At higher PAEs concentration (60 ng/g) the main bis(2-ethylhexyl) phthalate (DEHP) sink were roots whereas at lower concentrations (30 ng/g) most of DEHP was noted in lettuce leaves implying that the fate of PAEs was governed not by the chemical structure of PAEs but rather partitioning (logKow).

Machine learning-assisted assessment of key meteorological and crop factors affecting historical mulch pollution in China

Degraded mulch pollution is of a great concern for agricultural soils. Although numerous studies have examined this issue from an environmental perspective, there is a lack of research focusing on crop-specific factors such as crop type. This study aimed to explore the correlation between meteorological and crop factors and mulch contamination. The first step was to estimate the amounts of mulch-derived microplastics (MPs) and phthalic acid esters (PAEs) during the rapid expansion period (1993–2012) of mulch usage in China. Subsequently, the Elastic Net (EN) and Random Forest (RF) models were employed to process a dataset that included meteorological, crop, and estimation data. At the national level, the RF model suggested that coldness in fall was crucial for MPs generation, while vegetables acted as a key factor for PAEs release. On a regional scale, the EN results showed that crops like vegetables, cotton, and peanuts remained significantly involved in PAEs contamination. As for MPs generation, coldness prevailed over all regions. Aridity became more critical for southern regions compared to northern regions due to solar radiation. Lastly, each region possessed specific crop types that could potentially influence its MPs contamination levels and provide guidance for developing sustainable ways to manage mulch contamination.

Exploring the potential of a new marine bacterium associated with plastisphere to metabolize dibutyl phthalate and bis(2-ethylhexyl) phthalate by enrichment cultures combined with multi-omics analysis

Phthalic acid esters (PAEs) plasticizers are virulent endocrine disruptors that are mixed into plastics while fabricating and can filter out once they release into the surrounding environments. Plastic surfaces serve as new habitats for microorganisms, referred to as ‘plastisphere’. Previous metagenomic investigations of the ‘plastisphere’ indicated that marine plastic surfaces may harbor microbes that degrade PAEs plasticizers. To our knowledge, the potential of microorganisms in the marine ‘plastisphere’ to metabolize PAEs is poorly understood. In this study, by screening the natural microbial community on plastic debris that had been deployed in situ for up to 20 months, a novel marine bacterium, Microbacterium esteraromaticum DEHP-1, was successfully isolated, which could degrade and mineralize 10–200 mg/L dibutyl phthalate (DBP) and bis(2-ethylhexyl) phthalate (DEHP). According to the results of gas chromatography-mass spectrometry (GC-MS) and whole genome mining of strain DEHP-1, we found that strain DEHP-1 may metabolize DBP by successive removal of the ester side chain by esterase 2518 to produce mono-butyl phthalate (MBP) and phthalic acid (PA), whereas the degradation of DEHP may take place by the direct action of monooxygenase 0132 on the fatty acid side chain of the DEHP molecule to produce di-n-hexyl phthalate (DnHP) and DBP, and then the subsequent hydrolysis of DBP by de-esterification to PA and finally into the tricarboxylic acid (TCA) cycle. Non-targeted metabolomics results showed that intracellular degradation of PAEs did not happen. However, exposure to PAEs was found to significantly affect pathways such as arginine and proline, riboflavin, glutathione and lysine degradation. Therefore, the intracellular metabolic behavior of strain DEHP-1 exposed to PAEs was proposed for the first time. This study sheds light on the metabolic capacity and strategies of bacteria in the marine ‘plastisphere’ to effectively degrade PAEs and highlights the importance of marine microbes in mitigating plastic poisonousness.

Accumulation, sources, and health risks of phthalic acid esters (PAEs) in road dust from heavily industrialized, urban and rural areas in southern Iran

In this research, a total of 51 road dust samples were collected from three districts (Asaluyeh, Bushehr, and Goshoui) in the south of Iran from April to June 2022 and analyzed for the concentration of 7 phthalic acid esters (PAEs) compounds. Asaluyeh was considered as an industrial area (near gas and petrochemical industries), Bushehr as an urban area, and Goshoui as a rural area (far from pollution sources). The PAEs concentration of the street dust samples was determined using a mass detection gas chromatography (GC/MS). The mean ± SD levels of ƩPAEs in samples from industrial, urban, and rural sources were 56.9 ± 11.5, 18.3 ± 9.64, and 5.68 ± 1.85 μg/g, respectively. The mean concentration levels of ƩPAEs was significantly (P < 0.05) higher in samples from the industrial area than urban and rural areas. The mean levels of di(2-Ethylhexyl) phthalate (DEHP) in industrial, urban, and rural areas were 20.3 ± 8.76, 4.59 ± 1.71, and 2.35 ± 0.98 μg/g, respectively. The results of the PCA analysis indicate that the likely major sources of PAEs in the road dust in the studied areas are the application of various plasticizers in industry, solvents, chemical fertilizers, waste disposal, wastewater (e.g., agricultural, domestic, and industrial), and the use of plastic films and plastic-based irrigation pipes in greenhouses. As well as, it was found that the non-cancer risk of exposure to dust-bound PAEs was higher for children than for adults. These values were <1 for both age groups (children and adults) and the exposure of inhabitants to PAEs in road dust did not pose a notable non-cancer risk. The cancer risk from exposure to DEHP in road dust was below the standard range of 10−6 in all three areas. Further studies that consider different routes of exposure to these contaminants are needed for an accurate risk assessment. Moreover, since higher PAEs level was found in industrial area, decision-makers should adopt strict strategies to control the discharging of pollution from industries to the environment and human societies.

Oxidative stress and energy metabolic response of Isochrysis galbana induced by different types of pristine and aging microplastics and their leachates

The aging process and leachate composition of different types of MPs (PS, PS-NH2, PS-COOH and PMMA) with a particle size of 1.0 μm were characterized, and marine microalgae Isochrysis galbana OA3011(I. galbana) was used as test organism to investigate the 96 h toxic effects of MPs before and after aging as well as leachate exposure. Except for polymethyl methacrylate (PMMA), all other tested microplastics showed significant aggregation in seawater, which increased with the presence of surface amino and carboxyl groups, in addition, the increase in polymer dispersibility index (PDI) values after aging reflected more severe aggregation. Fourier transform infrared spectrometer (FTIR) showed that the surface amino groups were shed during the aging of PS-NH2, which can likewise be demonstrated by the change in surface electric potential from positive to negative before and after aging. PMMA, due to the addition of plasticizers (HEHP and DIBP detected in high concentration) and its own structure, has stronger resistance to aging than the other three microplastics, and no significant aging phenomenon occurs. As for I. galbana, growth inhibition, oxidative stress and energy metabolism were tested after exposure to different microplastics and their leachate. It was found that high concentrations of A-PS had a greater negative impact on I. galbana, while the toxic effects of PS-NH2 and PS-COOH on I. galbana behaved in a diametrically opposite way before and after aging compared to PS with the inhibitory effect decreasing after aging, which was caused by the shedding of surface groups. As for PMMA, the differences in the toxic effects on microalgae before and after aging were not significant. The inhibitory effect of low concentrations of PAEs (Phthalate acid esters) in the leachate of PS-COOH on I. galbana was not significant, and the stronger inhibitory effect of 4 d L-PS-NH2 was presumed to be the shedding of positively charged groups.

Factors controlling the heavy metal ion activity in soil contaminated by microplastics with different mulch durations: Partial least squares path model

Film covers have been widely applied worldwide. However, the effects of long-term plastic film mulching use on heavy metal (HM) activity in soil remain unclear. This study focused on farmland in the upstream part of the Pearl River in China and collected 103 soil samples after 2, 5, and 15 years of plastic film mulching. The main environmental factors controlling microplastics (MPs), plasticizer phthalic acid esters (PAEs), HM pollution characteristics, and HM activity were analyzed. The results showed that Polyethylene (PE) and di(2-ethylhexyl) dicyclohexyl phthalate (DCHP) were the main MPs and PAEs, respectively. The abundance of MPs and the concentrations of free HM ions (Cd, Cu, and Ni) in the soil solution increased with increasing plastic film mulching duration. The Partial Least Squares Path Model (PLS-PM) indicated that after plastic film mulching, soil chemical properties (pH/amorphous Fe) and biological properties (Dissolved organic carbon/ Easily oxidizable carbon/Microbial biomass carbon) were the main controlling factors for free and complexed HM ions (Cd, Pb, Cu, and Ni). These results suggest that, after plastic film mulching, MPs indirectly regulate HM activity by altering soil properties. This study provides a new perspective for the management of MPs and HM activities in agricultural ecosystems.

Combined Astragalus, vitamin C, and vitamin E alleviate DEHP-induced oxidative stress and the decreased of insulin synthesis and secretion in INS-1 cells

Di-(2-ethylhexyl)-phthalate (DEHP), a common Phthalic acid ester (PAEs), has been reported to be associated with diabetes mellitus, yet the underlying mechanisms remain unknown. Combined nutrient interventions have been shown to alleviate the diabetic toxicity of DEHP. However, the effects and mechanisms of the combined intervention of Astragalus and vitamins (C and E) are currently unknown. In this study, we investigated the potential mechanisms of DEHP-induced diabetes mellitus through transcriptome analysis and vitro experiments using rat insulinoma cells (INS-1 cells). Furthermore, we explored the protection of the combined Astragalus, vitamin C, and vitamin E on DEHP-induced diabetes mellitus through these mechanisms. INS-1 cells in the logarithmic growth period were exposed to 125 umol/L DEHP followed by high-throughput sequencing analysis. The cell proliferation inhibition rate was determined using MTT assay for each group, and the cell apoptosis rate and intracellular ROS level were measured using flow cytometer. Finally, insulin levels and markers of oxidative stress were detected using ELISA kits in different groups. A total of 372 differentially expressed genes were found between the 125 umol/L DEHP and control groups, subsequent functional enrichment analyses indicated that DEHP induced oxidative stress and disturbed insulin levels. In INS-1 cells, the rate of cell proliferation inhibition, apoptosis, and the degree of oxidative stress increased concentration-dependently with increasing DEHP concentrations, while antioxidant intervention could reverse these changes. Insulin synthesis and secretion decreased after 240 μmol/L DEHP exposure stimulated by 25 mM glucose in INS-1 cells, also could antioxidant intervention alleviate these reductions. Based on these results, the underlying mechanism of DEHP impairing the function of INS-1 cells might be through apoptosis pathways induced by oxidative stress and direct reduction of insulin levels (both synthesis and secretion), while the optimal combination of Astragalus and vitamins (C and E) could exert an alleviating effect.

A Critical Review of Analytical Methods for the Quantification of Phthalates Esters in Two Important European Food Products: Olive Oil and Wine.

Phthalic acid esters (PAEs) are a class of chemicals widely used as plasticizers. These compounds, considered toxic, do not bond to the polymeric matrix of plastic and can, therefore, migrate into the surrounding environment, posing a risk to human health. The primary source of human exposure is food, which can become contaminated during cultivation, production, and packaging. Therefore, it is imperative to control and regulate this exposure. This review covers the analytical methods used for their determination in two economically significant products: olive oil and wine. Additionally, it provides a summary and analysis of information regarding the characteristics, toxicity, effects on human health, and current regulations pertaining to PAEs in food. Various approaches for the extraction, purification, and quantification of these analytes are highlighted. Solvent and sorbent-based extraction techniques are reviewed, as are the chromatographic separation and other methods currently applied in the analysis of PAEs in wines and olive oils. The analysis of these contaminants is challenging due to the complexities of the matrices and the widespread presence of PAEs in analytical laboratories, demanding the implementation of appropriate strategies.

DEHP and DBP, common phthalates, induce glucose metabolism disorders in rats via oxidative damage of PI3K/Akt/GLUT4 signaling

Phthalic acid esters (PAEs) are environmental endocrine disruptors thought to interfere with glucose metabolism in humans. Most of the related research has focused on population epidemiological studies, with the underlying mechanisms remaining unresolved. Using an in vivo animal model, we examined the effects of oral administration of two commonly used PAEs [di(2-ethylhexyl) phthalate (DEHP) and dibutyl phthalate (DBP)] on glucose homeostasis and insulin secretion. DEHP (750 mg/kg, 1/40 LD50), DBP (500 mg/kg, 1/40 LD50), and DEHP (750 mg/kg) + DBP (500 mg/kg) exert an influence on glucose metabolism and elicit a reduction in insulin sensitivity in rats. Furthermore, these substances induce detrimental effects on the structure and functionality of pancreatic β-cells. DEHP and/or DBP triggered an increase in plasma malondialdehyde (MDA) and reduction in superoxide dismutase (SOD) activity; a reduction in the phosphorylation of phosphatidyl inositol 3 kinase (PI3K) and phospho-protein kinase B (p-Akt473) proteins; an increase in the relative expression of Bax, Caspase-8, cleaved-Caspase-9, and cleaved-Caspase-3; and a reduction in the relative expression of Bcl-2-related Bax in pancreatic tissue and of gastrocnemius glucose transporter 4 (GLUT4) in the gastrocnemius muscle. Based on these findings, these PAEs can disrupt glucose metabolism, possibly via oxidative damage of the PI3K/Akt/GLUT4 pathway; this damage induces pancreatic β-cell apoptosis, affects pancreatic β-cell function, and affects glucose metabolism and insulin resistance in rats. To the best of our knowledge, this study was the first to show that the combined effect of the two PAEs affects glucose metabolism and insulin resistance in rats that is significantly higher than the effects of each PAE. Thus, safety standards and studies do not consider this effect as a significant oversight when blending PAEs. We assert that this must be addressed and corrected for establishing more impactful and safer standards.

Exploring the Occurrence of Organic Contaminants in Human Semen through an Innovative LC-HRMS-Based Methodology Suitable for Target and Nontarget Analysis.

Understanding the potential impact of organic contaminants on male fertility is crucial, yet limited studies have examined these chemicals in semen, with most focusing on urine and blood. To address this gap, we developed and validated a robust LC-HRMS methodology for semen analysis, with a focus on polar and semipolar chemicals. Our methodology enables the quantitative (or semiquantitative) analysis of >2000 chemicals being compatible with suspect and nontarget strategies and providing unprecedented insights into the occurrence and potential bioaccumulation of diverse contaminants in this matrix. We comprehensively analyzed exogenous organic chemicals and associated metabolites in ten semen samples from Spanish participants collected in an area with a large presence of the chemical industry included in the LED-FERTYL Spanish study cohort. This investigation revealed the presence of various contaminants in semen, including plastic additives, PFAS, flame retardants, surfactants, and insecticides. Notably, prevalent plastic additives such as phthalic acid esters and bisphenols were identified, indicating potential health risks. Additionally, we uncovered previously understudied chemicals like the tire additive 2-mercaptobenzothiazole and specific organophosphate flame retardants. This study showcases the potential of our methodology as a valuable tool for large-scale cohort studies, providing insights into the association between contaminant exposure and the risk of male fertility impairments.

Phthalate acid ester release from microplastics in water environment and their comparison between single and competitive adsorption.

The ability of microplastics (MPs) to adsorb environmental pollutants has been extensively studied. However, little is known about the ability of MPs to release inherent additives and the interaction between them. This paper explored the effects of environmental factors on the release of phthalic acid esters (PAEs) from three different types of microplastics (polyethylene microplastics (PE-MPs), polypropylene microplastics (PP-MPs), and polystyrene microplastics (PS-MPs)) by simulating water environments, as well as the differences in the adsorption of one or more PAEs by MPs. The results showed that the types of MPs, single environmental factors, and combined environmental factors had a great influence on the release of di(2-ethylhexyl) phthalate (DEHP). In the influence of a single environmental factor, the releasing amount of DEHP increased significantly. When the pH value increased from 5 to 9, the release of three PAEs from all MPs decreased. Moreover, under the combined influence of three environmental factors, the DEHP release from PP-MPs was most affected by environmental factors, and the order of influence of the three environmental factors was ionic strength > organic matter > pH. The DEHP release of PS-MPs was the highest (0.058 ± 0.023 μg/L), followed by PP-MPs (0.038 ± 0.010 μg/L) and PE-MPs (0.035 ± 0.008 μg/L). Adsorption kinetics and isotherm fitting showed that the adsorption process of the three MPs was suitable for the pseudo-second-order kinetic model, and the Freundlich adsorption isotherm had a higher fitting degree. Compared with single adsorption, the competitive adsorption of three PAEs increased the adsorption capacity of DEHP and decreased the adsorption capacity of dibutyl phthalate (DBP) and diisobutyl phthalate (DIBP). These findings help predict the potential of MPs to release toxic additives under different environmental conditions.

Study on the mechanisms of DMP degradation by electro-Fenton method modified by single atomic-Co doped carbon-based catalyst

Electro-Fenton technology is an advanced oxidation process for phthalic acid esters (PAEs) that builds upon traditional Fenton technology, enhancing its efficiency, selectivity, and flexibility. Thus, cobalt-doped carbon-based catalyst (Co@NSC) were prapered via melamine doped by cobalt (Co) and calcinated at high temperature, and showed excent mesoporous structure (mainly range from 1.3 to 16 nm), high surface area (223.26 m2/g) and big pore volume (0.392 cm3/g). And the result of electrochemical performance test showed that the two-electron oxygen reduction ability of the material can be effectively improved in the case of Co doping. DMP can be degraded within 30 min by using Co@NSC as an electro-Fenton cathode, with excellent degradation efficiency (100 %) and total organic carbon (TOC) mineralization rate (about 40 %) even under the optimal conditions. The exploration of the mechanism demonstrated that OH and 1O2 were the main contributors. According to density functional theory (DFT) theoretical calculation and liquid chromatograph-mass spectrometer(LC-MS) results, the vulnerable site and degradation path of DMP were reasonably speculated. The ecotoxicity evaluation of the degradation products showed that the the toxicity of DMP has been significantly reduced during degradation process by Co@NSC electro-Fenton. Thus, Co@NSC is a cost-effective and promising catalyst, in which all the metal sites were utilized while the cost of metal were significantly minimized.

Comparative phytochemical and bioactivity studies on two related Scorzonera L. species: A chemotaxonomic contribution

Scorzonera L. (Asteraceae) is considered a taxonomically difficult genus with its more than 160 species. Scorzonera bella (SB) and S. veratrifolia (SV) species have been treated as synonyms since 1975. Recent botanical studies suggested the separation of the two taxa based on phenetic dissimilarities. Isolation, LC-MS/MS (including 53 phytochemicals as standard), and GC-MS (followed by library search) analyzes were conducted on the aerial parts of the plants to compare their phytochemical compositions and contribute to the classification of the two taxa. While flavonoid profile of SB was dominated by flavones, the majority of SV consisted of flavonols, among the analyzed standards. Nicotiflorin, the most abundant compound of SV, was the most notable difference which was not determined in SB. Kaempferol glycosides might be chemotaxonomic markers for the classification at subgenus levels. Caffeoylquinic acid esters were in common and similar amounts according to profiling and isolation results. Phytochemical compositions of nonpolar fractions of the plants differed significantly in phthalic acid esters, ursane, and hopane type triterpenoids which were only determined in SV. Phytochemical findings supported the separation of the two taxa. Antioxidant, anti-diabetic, anti-Alzheimer, and anti-hyperpigmentation potentials of the plants were evaluated in-vitro.

Unveiling the Nexus the link between water quality index and phthalic acid ester concentrations in Tigris River

Monitoring water quality in an aquatic system is a crucial objective in pursuing sustainable development, despite the challenges posed by water scarcity and the impact of climate change. The objective of the present study was to examine the water quality of the Tigris River along its course from the point of entry into Baghdad city to its exit, particularly in the presence of Phthalic Acid Esters (PAEs). In both dry and wet seasons and from five sites of the river, nine environmental factors (Turbidity, Total dissolved solids, pH, dissolved oxygen, Chloride, nitrate, phosphate, sulfate, and Biological oxygen demand) and three PAEs (di-n-butyl phthalate (DBP), di-isononyl phthalate (DiNP), and di-2-ethyl hexyl phthalate (DEHP)) were investigated. Results revealed that the river has high levels of turbidity and Total dissolved solids, slightly alkaline, and well-aerated (dissolved oxygen >7 mg/L). Chloride, nitrate, phosphate, and sulfate values varied between seasons, as high values were recorded in the wet season. Biochemical oxygen demand levels were higher during the dry season. The highest value of total PAEs (2.20 μg/L) was observed during the dry season, and the lowest value was in the wet season (1.16 μg/L). The HQ results revealed that the river was ranked as a moderate risk area. However the water quality index and environmental risk index classified the water quality as a poor category, with a high-risk score in the study sites within Baghdad city. Therefore, despite the acceptable limit of PAEs in the river's water (<3 μg/L), its presence is an early alarm to withdraw attention to its environmental risk. These findings highlight the need for appropriate measures to control and remove pollutants to ensure a safe and healthy water supply in the Tigris River.

Unraveling the crucial role of Mo2N from Fe/Mo bimetal MOF-derived catalyst in initiating Fe3+/Fe2+ redox cycle to activate peroxymonosulfate for dibutyl phthalate degradation

Phthalic acid esters (PAEs) pose serious health risks to humans and are difficult to remove by conventional sewage treatment processes. Herein, Fe2Mo3O8/MoO2/Mo2N composite (FMON) derived from bimetallic organic framework was used to activate peroxymonosulfate (PMS) for dibutyl phthalate (DBP) degradation. FMON exhibited an excellent catalytic effect with DBP removal efficiency of 92.4 % within 60 min. Mo2N showed a superior ability in promoting Fe3+/Fe2+ redox cycle. The reduction efficiencies of Fe3+ by Mo2N/MoO2 composite and MoO2 were 67 %–94 % and 11 %–23 %, respectively, in the homogeneous comparative experiment. Moreover, the ratio of Fe2+/Fe3+ in FMON increased significantly after the catalytic reaction. Fe element doping also enhanced the reuse stability and reduced the metal ion leaching of the catalyst. The degradation of DBP was mediated by a variety of reactive species, of which SO4−, OH and O2− were dominant. Fe element, Mo element and O vacancies were confirmed to exert significant contributions as active sites in the catalytic process. Three degradation pathways of DBP were obtained by DFT calculation and HPLC-MS analysis. And the toxicity of DBP degradation products was significantly reduced based on the assessment result of Toxicity Estimation Software Tool (T.E.S.T.). This study explored a novel Fe/Mo bimetallic catalyst with friendly Fe3+/Fe2+ cycling for environmental catalysis and provided new ideas for the treatment of PAEs wastewater.

Carbon and hydrogen isotope fractionation of phthalates during photocatalysis reactions in aqueous solution containing Fe(III) complexes or iron minerals

The hydrogen and carbon isotope fractionation factor (ε2H, ε13C) of dimethyl-, diethyl‑ and dibutyl phthalic acid ester during photosensitized degradation by artificial sunlight with Fe(III) ions and iron minerals (hematite, goethite and magnetite) in aqueous solution were examined by compound-specific isotope analysis (CSIA) in order to analyze the degradation mechanism. Hematite does not catalyze photosensitized degradation of phthalates. The correlation of 2H and 13C isotope fractionation (Λ = Δδ2H/Δδ13C) of phthalates with increasing chain length (dimethyl-; diethyl‑; and dibutyl-) were compared with values of the ∙OH radical model reaction with the aromatic ring as well as acidic and alkaline hydrolysis. The Λ values of die photosensitized reaction of diethyl phthalate with goethite (-5.1 ± 1.8) and magnetite (-18.9 ± 3.9) show a large difference compared to Fe(III) solutions (4.7 ± 0.9 to 4.8 ± 1.0) suggesting specific reaction mechanisms. The fractionation factors determined here have potential to characterize the degradation of phthalates catalyzed by photo-induced reaction of Fe(III), goethite and magnetite in natural system and in remediation approaches.

Model inversion and three-way decompositions in the analytical quality by design strategy for the determination of phthalates BY HS-SPME-GC-MS

In this work, strategies within Analytical Quality by Design (AQbD) with tools of the Process Analytical Technology (PAT) were used in the development of a head space-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) procedure for the multiresidue analysis of four phthalic acid esters, benzyl butyl phthalate, bis(2-ethylhexyl) phthalate, dibutyl phthalate and diethyl phthalate (regulated by Commission Regulation (EU) No 10/2011). The approach is based on the fact that the intended quality of the resulting chromatograms is defined in terms of the loadings on the sample mode of a Parallel Factor Analysis (PARAFAC2) decomposition. These loadings are the ones used for the inversion of a Partial Least Squares (PLS2) prediction model that has been previously fitted. The inversion gives the experimental conditions that represent a compromise solution in terms of the desired or target values of the responses (Critical Quality Attributes, CQAs), while guaranteeing that these experimental conditions are inside the experimental domain of the Control Method Parameters (CMPs).This strategy results in experimental conditions of extraction time and temperature that lead to a chromatogram of predefined quality for the four analytes together, with the subsquent saving of time and energy. The experimental conditions achieved have been experimentally verified and figures of merit of the analytical method have been determined. The method has been applied to a case study, bottled natural and flavoured mineral water. Concentrations around 0.3 μg L−1 of dibutyl phthalate have been found in 5 of the 22 bottles of water analysed.