Dibutyl Phthalate Research Articles

Pollution Status, Ecological Effects, and Bioremediation Strategies of Phthalic Acid Esters in Agricultural Ecosystems: A Review.

Phthalic acid esters (PAEs) are common organic contaminants in farmland soil throughout agricultural systems, posing significant threats to human health and thus closely associated with food safety concerns. Here, we consolidate the latest findings regarding the distribution, ecological effects, bioremediation methods, and microbial degradation pathways of PAEs in agricultural ecosystems. Generally, di(2-ethylhexyl) phthalate (DEHP), di-n-butyl phthalate (DnBP), and di-isobutyl phthalate (DiBP) exhibit the highest detection frequencies and concentrations in soil, air and agricultural products. The presence of these PAEs in agricultural ecosystems can significantly affect soil and plant-associated microbial communities, leading to decreased yield and quality of agricultural products. Bioremediation techniques, such as microbial degradation and phytoremediation, are frequently explored to address these issues. Overall, this review provides a comprehensive overview of current research on PAEs in China's agricultural systems and offers insights into potential problems and future research directions.

Occurrence, bioaccumulation, and partitioning of phthalate acid esters in the third largest freshwater lake (Lake Taihu) in China

Phthalate acid esters (PAEs) are a category of plasticizers that are ubiquitous in freshwater environments attributable to extensive utilization. We collected water, suspended particulate matter (SPM), surface sediments, phytoplankton, and zooplankton from 23 sampling sites to investigate and complement the occurrence, bioaccumulation, and partitioning of five PAEs including dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), and di (2-ethylhexyl) phthalate (DEHP) in the third largest freshwater lake (Lake Taihu) of China. PAEs were extracted using Soxhlet extraction and solid phase extraction, and determined by gas chromatography-mass spectrometry. The average concentrations of the five PAEs in the water column, SPM, sediments, phytoplankton, and zooplankton of Lake Taihu were 1.93±1.57μgL-1, 765±766μgg-1, 1.68±1.47μgg-1, 1358±1877μgg-1, and 72.7±134μgg-1, respectively. DBP and DEHP were the dominant PAE congeners in the five environment compartments. The logarithmic concentrations of DBP, BBP, and DEHP in the SPM were negatively correlated with the logarithmic content of the SPM. Biodilution significantly impacted the occurrence of PAEs in the plankton. Bioaccumulation of PAEs was found in the plankton with log BCF (bioconcentration factor) in the phytoplankton ranging from 1.78±0.86 to 4.13±1.23 and log BAF (bioaccumulation factor) in the zooplankton varying from -0.10±0.26 to 3.04±0.64. Biomagnification of the PAEs from phytoplankton to zooplankton was not observed. DMP, DEP, and BBP migrated from sediments to water. DBP was in dynamic equilibrium in the sediment-water system. DEHP transferred from water to sediments. Our results provide crucial complementary knowledge on bioaccumulation and transfer of PAEs in planktonic food web, and their partitioning in different compartments of waters.

Phthalate esters in dusts from different indoor and outdoor microenvironment and potential human health risk: A case study in Beijing

Phthalate esters (PAEs) are widely used plasticizers that can easily migrate from plastic products, thereby presenting potential health risks through exposure. While PAE concentrations in dust have received increasing attention, there is still a lack of comprehensive understanding regarding their environmental distribution, composition profiles, and associated human exposure risks in Beijing. This study investigated the presence of seven PAEs in 124 dust samples collected from eight indoor and four outdoor microenvironment types across the Beijing metropolitan area. The PAEs were detected universally in all samples, with di(2-ethylhexyl) phthalate (DEHP), dibutyl phthalate (DBP) and di-iso-butyl phthalate (DIBP) as the predominant compounds, accounting for 91.78%-99.91% and 91.22%-99.76% of total PAE concentrations (Σ7PAEs) in indoor and outdoor dust, respectively. Indoor dust exhibited significantly higher Σ7PAEs (range: 45.33-1212.41 μg/g, mean: 130.61 μg/g) compared to outdoor dust (range: 2.10-5.41 μg/g, mean: 3.38 μg/g). Among indoor microenvironments, taxis had the highest Σ7PAEs (mean: 1250.59 μg/g), followed by private cars, print shops, residences, furniture shops, shopping malls, dormitories and offices. Outdoor Σ7PAEs levels decreased in the order of roads, residential areas, green belts, and parks. Estimated daily exposure doses through dust ingestion were significantly higher than those from dermal absorption and inhalation for five occupational groups (taxi drivers, print shop workers, road workers, office workers, jobless people), indicating dust ingestion as the primary exposure route, with DEHP and DBP as the main contributors. While current exposure levels may not present significant non-cancer risks based on hazard quotient and hazard index estimations, it’s noteworthy that DEHP may pose a carcinogenic risk to taxi drivers. Potential risks cannot be overlooked considering the absence of toxicity thresholds, additional exposure pathways, and possible cocktail effects from coexisting pollutants.

Female rat liver after sub-acute dibutyl phthalate treatment: Histological, stereological, biochemical, and global gene expression study

Although it has been recognized that females are more susceptible to chemical-induced liver injury, the effects of dibutyl phthalate (DBP), a widely used synthetic chemical, on female liver structure and function are under-researched. Here, we sought to investigate the effects of DBP on histological, stereological, and biochemical parameters, as well as global gene expression in female rat liver. Female Wistar rats were exposed to 100, 500, and 5000 mg DBP/kg diet for 28 days, corresponding to 8.6, 41.43, and 447.33 mg DBP/kg body weight (B.W.)/day, respectively. The highest dose (447.33 mg DBP/kg B.W./day) was between the no-observed-adverse-effect level (NOAEL) and the lowest-observed-adverse-effect level for liver toxicity, whereas two lower doses (8.6 and 41.43 mg DBP/kg B.W./day) were below the NOAEL. Analysis of hematoxylin and eosin-stained sections revealed an increased volume of hepatocytes, their nuclei and cytoplasm, while the volume of sinusoids decreased in DBP-exposed groups compared to the control. Examination of Periodic acid-Schiff-stained sections showed reduced glycogen content, which was the most prominent in the highest dose group. Increased glutathione S-transferase and catalase activities, and decreased GSH content and superoxide dismutase activity were observed in DBP-exposed groups. The mRNA sequencing revealed DBP-induced dose-specific changes in various genes and biological functions in female rat liver. The highest number of deregulated genes was observed in the 500 mg DBP/kg diet group. In summary, exposure to DBP caused significant liver microstructural changes, decreased glycogen content, disturbed the redox status, and affected global gene expression in female rat liver.

Phthalate ester and cholesterol profiles of blubber samples of the free-ranging Amazon River dolphin (Cetacea: Iniidae: Inia geoffrensis) in the Brazilian Amazon.

This study assessed the exposure of free-ranging Amazon River dolphins (Inia geoffrensis) to phthalate esters (PAE) in a remote area of the Brazilian Amazon. Blubber samples were analyzed for four PAEs - dimethyl phthalate, diethyl phthalate, dibutyl phthalate, and di(2-ethylhexyl) phthalate - and cholesterol contents to evaluate potential metabolic disturbances. All dolphins were contaminated with at least two PAEs, with DEHP (242.16ng/μL) and DBP (191.62ng/μL) being the most frequent, detected in 93% and 79% of the sample, respectively. Significant positive correlations were found between DBP and DEP (r=0.857), DEHP and DEP (r=0.794), and DBP and body length (r=0.642), suggesting bioaccumulation. Despite the cholesterol data not showing a correlation with the other findings, these results highlight PAE pollution in a supposedly pristine environment and their potential impact on the health and conservation of Amazon River dolphins' health and Amazonian ecosystem.

The herbicidal activities and biochemical characteristics of isolates from Murraya microphylla

The extracts of the twigs and leaves of Murraya microphylla showed different level herbicidal activities against Amaranthus retroffexus and Digitaria sanguinalis. Bioguided isolation was performed to obtain eight pyranocarbazoles (1-8), four coumarins (10-13), two flavones (15 and 16), one dibutyl phthalate (9), and one sterol (14), including a new pyranocarbazole (1) and a new natural product (9). Petri dish assay showed that pyranocarbazoles and coumarins were the main herbicidal components of M. microphylla extract, and their structure–activity relationships were ulteriorly elucidated. As the representatives of pyracarbazole and coumarin, 7 and 10 showed significant herbicidal activity compared with the positive control (Nicosulfuron), with the IC50 values 82.93 and 16.34 μg mL−1 against shoots and roots of A. retroffexus seedling, respectively. Experimental results of morphology, physiology and biochemistry indicated that the inhibition on seed germination by 7 and 10 was mainly related to energy deficiency, while the inhibition of seedling growth was mainly related to decreased chlorophyll content, reduced root hairs, and cell membrane damage. Therefore, 7 and 10 have the potential to develop new plant herbicides directly or as lead compounds.

Effect of Natural Oils as Permeation Enhancer for Transdermal Delivery of Telmisartan

Aim of the present study was to determine the feasibility of natural oils as permeation enhancers for the development of a transdermal delivery system of telmisartan. The penetration-enhancing potential of olive oil and clove oil on in-vitro permeation of telmisartan across shed snake skin was studied. The patches were evaluated for their physicochemical characteristics, in-vitro drug release, and in-vitro permeation studies. The system containing hydroxypropyl methylcellulose and Eudragit L-100 (6:4) as matrix forming agents and dibutyl phthalate (20%) as plasticizer was selected as the best formulation for incorporation of natural oils as penetration enhancers. All transdermal patches were found to be uniform with respect to physical characteristics. Formulation (T7) containing 10% olive oil was found to be a promising natural permeation enhancer for transdermal delivery of telmisartan with the greatest cumulative amount of drug permeated (1536 μg/cm2) over 24 h. The studies indicated that the feasibility of transdermal delivery of telmisartan as a patch is likely to suffice the therapeutic requirement.

Unveiling phytochemicals and antioxidant, cytotoxic, anti-thrombotic, anti-inflammatory, and antibacterial activities from the leaves of Dalbergia stipulacea (Roxb.)

The study was aimed to conduct phytochemical investigation and assess the in vitro antioxidant, cytotoxic, anti-thrombotic, anti-inflammatory and antibacterial properties of crude methanol extract of Dalbergia stipulacea leaf and its various extractives. All the fractions contain quinines, alkaloids, flavonoids, tannins, resins, glycosides, and flavonoids, while crude methanol, petroleum ether, and ethyl acetate fractions contain saponins and steroids in qualitative phytochemical analysis. In GC-MS/MS technique, a total of 44 phytoconstituents were identified and characterized, where 3-O-Methyl-D-glucose (22.80 %), 8,11,14-Docosatrienoic acid, methyl ester (19.86 %), pentadecanoic acid, methyl ester (14.17 %), 13-docosenamide (6.62 %), nonadecanoic acid, methyl ester (4.62 %), and phytol (3.04 %) were most prominent. In addition, some promising bioactive constituents, such as pantolactone, aromandendrene, D-allose, loliolide, neophytadiene, dibutyl phthalate, kolavenol, and squalene are present in the leaf of D. stipulacea plant species. Petroleum ether soluble fraction (PESF) of the plant had the highest phenolic content (27.34 mg of GAE/gm) and showed the most effective DPPH free radical scavenger with a half maximal inhibitory concentration (IC50) value of 3.87 μg/mL. The PESF also exhibited cytotoxicity with median lethal dose (LC50) value of 2.76 μg/mL compared to the standard medication vincristine sulfate (LC50 = 0.45 μg/mL) in brine shrimp lethality bioassay. Compared to streptokinase (63.34 %), aqueous soluble fraction (AQSF) displayed the highest percentage of clot lysis (38.61 %). The PESF exhibited the most significant suppression of heat-induced hemolysis (32.61 %) and hypotonic solution-induced hemolysis (33.86 %), respectively, revealing promising anti-inflammatory properties. In addition, the methanol extract and its fractions exerted promising antibacterial properties with notable zone of inhibition (6–25 mm) compared to ciprofloxacin (17–37 mm). The current evidence supports the traditional medicinal applications of the plant, particularly its ability to act as an antioxidant, cytotoxic, thrombolytic, anti-inflammatory, and antibacterial agent. However, further phytochemical isolation and in vivo screening is necessary to discover new drugs from the leaf of D. stipulacea plant species based on the current evidence.

Innovative Potentiometric Quantification of Flutamide Using Novel Ion-Selective Electrodes with Sulfonphthalein Dyes

Two potentiometric sensors, referred to as ion-selective electrodes (ISE)-A and ISE-B, were constructed and validated to quantify the flutamide (FA) in drug formulations, extended to analyse human urine samples infused with drugs. Bromocresol green and bromophenol blue were used as ion-pair complexing agents in the construction of ISE-A and ISE-B, respectively. Dibutyl phthalate served as a plasticizer within a polyvinyl chloride matrix, with tetrahydrofuran as the solvent. The methods demonstrated linearity over the ranges of 2.5 x 10-6 to 2 x 10-3 M and 5 x 10-6 to 1.8 x 10-3 M for ISE-A and ISE-B, respectively. The Nernstian slop of 58.8 ± 0.96 and 62.11 ± 0.83 were exhibited by the proposed methods employing ISE-A and ISE-B, respectively, within a response time of 25 seconds and were effective for the analysis of FA over a period of 52 days within a pH range of 1.0 to 4.2. The coefficient of determination (R2) was very close to one, indicating an excellent fit between the actual and measured data. For ISE-A, the computed limits of detection and quantification were 0.82 x 10-6 M and 2.45 x 10-6 M, respectively, and 1.64 x 10-6 M and 4.86 x 10-6 M for ISE-B. The ICH recommendations were followed during the validation process, which evaluated the methodologies' robustness, ruggedness, sensitivity, accuracy, precision, and selectivity.

Unraveling the mechanisms of organic contamination on gold pulse compression gratings: From cluster formation to stratified adsorption

Organic contamination on gold pulse compression gratings significantly hampers the performance of high-power laser systems under intense laser irradiation. Investigating the adsorption mechanisms of organic contaminants on microstructured gratings is essential for addressing contamination issues and mitigating damage. In this article, we determine the microstructured surface aggregation characteristics of volatile dibutyl phthalate (DBP), the stratified distribution pattern of amorphous DBP clusters, and the distribution points of molecules within microstructures using experiments and cross-scale simulations (molecular dynamics and quantum chemistry). Our analysis of the Reduced Density Gradient (RDG) and charge transfer reveals that adsorption between organic molecules and the gold substrate primarily stems from non-covalent van der Waals and electrostatic forces induced by ester functional groups. Based on this theoretical study, we propose the "molecule-substrate" and "bimolecular" adsorption modes of DBP to elucidate the adsorption mechanisms. Investigating organic compounds' distribution and adsorption mechanisms on optical component surfaces is fundamental to high-power laser-induced damage studies. These insights facilitate the efficient, non-destructive removal of organic contaminants from gold gratings, enhancing the energy output threshold of inertial confinement fusion devices.

Re-sensitization of imipenem-resistant Pseudomonas aeruginosa and restoration of cephalosporins susceptibility in Enterobacteriaceae by recombinant Esterase B.

Sphingobium sp. SM42 Esterase B (EstB) is an enzyme with a dual function in degrading dibutyl phthalate (DBP) and catalyzing the cleavage of the C-S bond in C3-sidechains of the dihydrothiazine ring of cephalosporins, generating more active β-lactam derivatives. Global prokaryotic genome analysis revealed the existence of a gene identical to estB in Pseudomonas aeruginosa strain PS1 suggesting a horizontal gene transfer event involving estB. To investigate the effect of ectopic expression of EstB in the periplasm of Pseudomonas aeruginosa and several Enterobacteriaceae on antibiotic susceptibility levels, plasmid, pEstB, carrying a recombinant EstB fused with the signal peptide from Escherichia coli outer membrane protein A (OmpA) for periplasmic localization was constructed. The expression of EstB in the periplasm of P. aeruginosa and the Enterobacteriaceae: E. coli, Klebsiella pneumoniae, and Salmonella enterica serovar Typhi, increased susceptibility to carbapenems and cephalosporins. EstB reversed the imipenem resistance of P. aeruginosa ΔmexS and restored the changes in susceptibility to cephalosporins conferred by the downregulation of the outer membrane proteins, OmpK35 and OmpK36, in K. pneumoniae ΔramR-ompK36 to wild-type level. The introduction of EstB to the periplasmic space of Gram-negative bacteria can increase carbapenem and cephalosporin susceptibility.

Protective effects of black ginseng on testicular toxicity induced by Di-n-butyl phthalate in rats

ABSTRACT Di-n-butyl phthalate (DBP) is a phthalate-based material used as a plasticizer to soften polyvinyl chloride, and classified as an endocrine disruptor with antiandrogen effects. Exposure to DBP induces oxidative stress in rat testes, resulting in testicular toxicity. Black ginseng (BG) exhibits a higher antioxidant activity than white or red ginseng following repeated heat treatment and processing. This study aimed to investigate whether the antioxidant activity of BG might protect against DBP-induced testicular toxicity in juvenile Sprague-Dawley rats. A significant decrease in testicular weight was observed in most groups treated with DBP alone or in combination with BG. However, a significant testicular weight increase was detected after exposure to BG (10 ml/kg) + DBP (500 mg/kg). The epididymal weight was significantly reduced with associated histological changes including irregular arrangement, atrophy of seminiferous tubules and Sertoli cells, and Leydig cell damage following exposure to DBP alone as well as BG (2.5 ml/kg) + DBP (500 mg/kg). However, no marked changes were observed in the shape of seminiferous tubules in control and BG + DBP groups. A significant decrease in serum testosterone levels was found after exposure to DBP, but no marked alterations in the BG + DBP groups. Protein expression levels of nuclear factor erythroid-derived 2-related factor (Nrf2), NAD(P)H dehydrogenase 1 (NQO1), and, heme oxygenase-1; (HO-1) were significantly higher following DBP treatment, but lowered in the BG + DBP groups. Evidence indicates that BG exerts a protective effect against DBP-induced testicular toxicity in rats.

Developmental toxicity and mechanism of dibutyl phthalate on the development of subintestinal vessels in zebrafish

Background: The dibutyl phthalate (DBP) is a member of the phthalate family and is widely used as a plasticizer in daily life and production. However, the influence of DBP on the vascular developmental remains unclear. Methods: In this study, we used zebrafish as a model organism to investigate the effects of DBP on vascular development in vivo. Death curves of zebrafish at different concentrations of DBP exposure and different times incubation were made firstly. Zebrafish embryos after fertilization for 5.5 h were exposed to different concentrations of DBP solution (0, 0.4, 0.8, 1.2 mg/L), the body length, yolk sac absorption area, mortality and heart rate of zebrafish were measured, and the number and area of sprouting of ventral vessels were quantified by transgenic fish system. Reactive oxygen species (ROS) in zebrafish embryos were observed by DCFH-DA staining. Super oxide dimutese (SOD) and catalase (CAT) were determined with ELISA kits. Results: We found that DBP increased the oxidative stress level of zebrafish exposed to DBP, and the genes related to vascular development also increased. Meanwhile, the activities of SOD and CAT were greatly decreased after DBP exposure. In the rescue experiment, we found that the antioxidant astaxanthin and the small molecule VEGF inhibitor ZM-306,416 can reverse the vascular dysplasia caused by DBP. Conclusions: DBP induced vascular developmental toxicity by enhancing oxidative stress levels, activating HIF pathway, and interfering with the expression of vascular development-related pathways in zebrafish, results in the abnormal development of the subintestinal vessels in zebrafish.

A “super-off” photoelectrochemical biosensor based on Cu-BTC nanozyme quenching strategy for the detection of dibutyl phthalate plasticizer

Ultrasensitive detection of phthalic acid (PAEs) is an extremely critical mission in environmental monitoring. We designed a “super-off” photoelectrochemical (PEC) biosensor by using MoO3/Bi2MoO6 as photoanode and copper(II) benzene-1,3,5-tricarboxylate (Cu-BTC) nanozyme as highly efficient signal quencher. It was found that the PEC signal of MoO3/Bi2MoO6 photoelectric material is very sensitive to the concentration of co-reactor H2O2. Therefore, a target-triggered endonuclease-assisted recycle was employed to convert the target DBP into amount of output DNA, which can trigger the assembly of DNA nanonet for the immobilization of Cu-BTC nanozyme. Thanks to the peroxidase-like activity of Cu-BTC, a “super off” photocurrent was observed due to the consumption of electron donor H2O2 in the electrolyte. Compared with the traditional quenching strategies such as steric hindrance and light energy competition, this enzymatic reaction on the electrode interfaces is more effective to induce the distinct decrease of photocurrent for analysis. Ultimately, the constructed PEC sensor exhibited a broad linear range from 1 fM to 100 nM and a detection threshold of 0.3 fM. This work highlights the significance of using peroxide-mimic enzyme as a signal amplifier in PEC sensing platform for environmental monitoring.

Occurrence, migration, and assessment of human health and ecological risks of PFASs and EDCs in groundwater of Northeast China

Northeast China as an important base of grain production in China, has been suffering from potential groundwater pollution due to the excessive and prolonged application of fertilizers and pesticides. However, exploration of emerging contaminants pollution in groundwater and assessment of human health and ecological risks caused by large-scale agricultural activities have been relatively scarce. This study collected groundwater samples from typical agricultural areas in Northeast China to investigate the extent of contamination by nitrate, per- and polyfluoroalkyl substances (PFASs) and endocrine-disrupting compounds (EDCs), and then compared the levels of these pollutants with those in other regions of China. Groundwater nitrate pollution caused by strong agricultural activity is widespread in Northeast China, with nitrate-nitrogen (NO3N) concentrations exceeding 10 mg/L in as many as 40.3 % of 429 samples. 8 types of PFASs (3.7–7.1 ng/L) and 11 types of EDCs (18,114.0–62,029.8 ng/L) were detected in the collected groundwater samples. Using the Risk Quotient (RQ) method, this study assessed ecological risk and found that the risk level of perfluorooctane sulfonate (PFOS) was higher than that of other PFASs. The groundwater EDCs risks in Northeast China was higher compared to other regions in China, with dibutyl phthalate (DBP), Di-(2-ethylhexyl) phthalate (DEHP), Bisphenol A (BPA) having high ecological risk levels. Nitrate, PFASs and EDCs have been detected in deep groundwater (70–100 m depth), indicating that the deeper aquifers could be significantly threatened by pollutants due to human activities. Fertilizers, pesticides, domestic wastewater, and industrial discharges are major sources of groundwater pollutants in the agricultural regions. Industrial-sourced EDCs were widely detected in groundwater of agricultural area, suggesting that the transport of these pollutants is very active in groundwater system. Groundwater monitoring and pollution prevention are extremely urgent, especially for emerging contaminants. This study can provide important warnings and water resource management references for other agricultural areas affected by intensively agricultural activities in the world.

Harnessing landfill-derived Bacillus subtilis (LLS-04) for bio-electrodegradation of di-butyl phthalate: Comprehensive toxicity assessment across multiple biological models

Di-butyl phthalate (DBP), a pervasive environmental contaminant, poses significant ecological and health risks due to its persistence and toxicity. This study investigates the potential of a landfill-derived Bacillus subtilis strain (LLS-04) in bio-electrodegradation of DBP, alongside a comprehensive toxicity assessment across multiple biological models. Bio-electrodegradation efficiency was compared to biodegradation and electrodegradation, revealing that bio-electrodegradation achieved a remarkable 98.57 % reduction in DBP concentration significantly outperforming the other methods. This enhanced degradation was attributed to improved microbial activity and enzyme production, as indicated by higher protein content and increased esterase and dehydrogenase activities in the bio-electrodegradation system. The optimized conditions facilitated efficient degradation, with HPLC-MS/MS analysis confirming the breakdown of DBP into non-toxic end products via a proposed metabolic pathway. A comprehensive toxicity assessment, including in-silico analysis, in-vitro cytotoxicity and brine shrimp lethality assays, demonstrated a significant reduction in toxicity of BES treated effluent compared to DBP untreated effluent. Furthermore, in-vivo toxicity studies using animal model supported these findings, demonstrating reduced toxicity in the BES treated effluent compared to the DBP untreated effluent. Overall, these findings highlight the potential application of bio-electrodegradation in bioremediation strategies for phthalate pollution, offering an effective solution for reducing both DBP concentration and its environmental toxicity.

Rapid quantitative analysis of semi-volatile organic compounds in indoor surface film using direct analysis in real time mass spectrometry: a case study on phthalates

Abstract. Direct analysis in real time mass spectrometry (DART-MS) has recently emerged as a promising approach for measuring semi-volatile organic compounds (SVOCs) on indoor surface films. However, its broader application in indoor environments is limited by low measurement repeatability and no separation of isomers. Herein we developed a sampling suite of indoor surface films for DART-MS analysis, optimized settings of DART to obtain higher analytical performance, and demonstrated the possibility of separating isomeric compounds using tandem mass spectrometry (MS/MS). Two pairs of isomeric phthalate esters, including di(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) and diisobutyl phthalate (DiBP) and di-n-butyl phthalate (DnBP), were used as examples for method optimization and validation. Under optimized conditions, the instrument responses for all four compounds exhibited good linearity (r>0.992) and acceptable repeatability (intraday relative standard deviation (RSD) < 11.0 %). The limits of quantification for the four phthalate esters ranged from 0.042 to 0.24 ng cm−2. The uncertainty in the separation of isomeric components using MS/MS was < 11.4 %, which is acceptable for real sample analysis. To further assess the developed method, we analyzed 10 film samples collected side by side in an occupied office. DnOP was not detected. The RSD among samples was 6.1 % for DEHP, 4.6 % for DnBP, and 10.4 % for DiBP, indicating the overall good repeatability of the collection and measurement method developed. With improved performance, the developed method increases the feasibility of the DART-MS technique for monitoring the dynamics of chemical composition of indoor surface films.

Association of joint exposure to organophosphorus flame retardants and phthalate acid esters with gestational diabetes mellitus: a nested case-control study

BackgroundOrganic phosphate flame retardants (OPFRs) and phthalate acid esters (PAEs) are common endocrine-disrupting chemicals that cause metabolic disorders. This study aimed to assess the association between joint exposure to OPFRs and PAEs during early pregnancy in women with gestational diabetes mellitus (GDM).MethodsSeven OPFRs and five PAEs were detected in the urine of 65 GDM patients and 100 controls using gas chromatography-tandem triple quadrupole mass spectrometry (GC-MS). The association of OPFRs and PAEs with GDM was assessed using logistic regression, weighted quantile sum (WQS) regression, and Bayesian kernel machine regression (BKMR) models.ResultsLevels of dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DEHP), diethyl phthalate (DEP), dimethyl phthalate (DMP), tris (2-butoxyethyl) phosphate (TBEP), tributyl phosphate (TBP), tris (2-chloroethyl) phosphate (TCEP), tris (1,3-dichloro-2-propyl) phosphate (TDCPP), tri-ortho-cresyl phosphate (TOCP), and triphenyl phosphate (TPHP) increased in the GDM group, and the OPFRs and PAEs, except for BBP and TMCP, were associated with GDM in the logistic regression analysis. In the WQS model, the mixture of OPFRs and PAEs was significantly positively associated with GDM (OR = 3.29, 95%CI = 1.27–8.51, P = 0.014), with TDCPP having the highest WQS index weight. BKMR analysis reinforced these results, showing that the overall association of joint exposure to the OPFRs and PAEs with GDM increased at exposure levels of the 55th to 75th percentiles. Independent exposure to TDCPP (OR = 1.42, 95%CI = 1.09–1.86, P = 0.011) and TBEP (OR = 1.29, 95%CI = 1.04–1.60, P = 0.023) were associated with an increased risk of GDM.ConclusionsEnvironmental exposure to OPFRs and PAEs is significantly associated with GDM. These findings provide evidence for the adverse effects of exposure to OPFRs and PAEs on the health of pregnant women.

Simulation study on heavy metals, phthalate esters, and organic halogens: Content and distribution characteristics during waste paper recycling.

Imported waste paper and recycled pulp may contain pollutants, posing potential environmental risks to the ecosystem of China. This study examined the presence and distribution patterns of heavy metals, phthalate esters (PAEs), and adsorbable organic halogens (AOX) in recycled pulp and production wastewater after various recycling processes of three typical restricted types of imported waste paper. The results indicated that the concentration ranges of heavy metals, PAEs, and AOX in the three types of imported recycled waste paper were 21.61-40.38mg/kg, 15.35-27.88mg/kg, and 19.21-57.72mg/kg, respectively. The comparative analysis with the initial waste paper demonstrated a reduction in heavy metal content in the recycled pulp by 17.80-49.75%, PAEs by 65.42-90.55%, and AOX by 32.80-42.34%. The average concentrations of these pollutants in wastewater were 0.85-1.66mg/L, 27.28-59.86mg/L, and 1.15-3.34mg/L, respectively. Chromium and lead were identified as the primary heavy metals present in the waste paper. Following pulping, No. 1 and No. 2 met the arsenic and lead levels specified in the "Reuse Fiber Pulp" standard (GB/T24320-2021), whereas No. 3 met these criteria after de-inking only. The main PAEs detected in the waste paper were dibutyl phthalate and di(2-ethylhexyl) phthalate, most of which were removed during the pulping stage. Significantly higher levels of AOX were observed in No. 2 and No. 3 than in No. 1, with a minimal impact on AOX removal from the pulp during the recycling process.

Detection of organic explosive residues from outdoor detonations using confocal Raman microscopy

The detection of post-blast residues in the aftermath of an explosion involving organic explosives with spectroscopic techniques is challenging as, typically, no microscopically visible unreacted particles remain after the explosion. However, some low-order explosions may leave visible particles behind, as well as the presence of significant amounts of unreacted material. In this study, four authentic open-air detonations using two simulated improvised explosive devices (IEDs) containing a mixture of military explosives (TNT and RDX), and two IEDs containing smokeless powder were conducted. The various materials they contained, including plastic, wood, and metal, were swabbed and extracted with acetone to create post-blast liquid extracts. The extracts were then dried and examined using confocal Raman microscopy, alongside a 50 ppm reference mixture of smokeless powder constituents, which was created to evaluate the effects of Raman scattering within the full smokeless powder mixture. Smokeless powder constituents, such as ethyl centralite, diphenylamine, nitroglycerin, and dibutyl phthalate, were successfully identified by comparison to the reference mixture on most substrates, with the exception of the paint stick (wood) substrate. TNT/RDX was also able to be identified in the extracts, with RDX crystals being observed in some dried extracts after solvent evaporation. However, the detection of TNT/RDX in the second detonation was unsuccessful, possibly due to an explosive chain reaction that was highly efficient. No trends were seen in substrate affinity for TNT/RDX. The challenges and benefits with the developed methodology for the detection of organic explosive residues from a variety of substrates are discussed in detail.