Diethylhexyl Phthalate Research Articles

Microplastics Reshape the Fate of Aqueous Carbon by Inducing Dynamic Changes in Biodiversity and Chemodiversity.

The interactions among dissolved organic matter (DOM), microplastics (MPs) and microbes influence the fate of aqueous carbon and greenhouse gas emissions. However, the related processes and mechanisms remain unclear. Here, we found that MPs determined the fate of aqueous carbon by influencing biodiversity and chemodiversity. MPs release chemical additives such as diethylhexyl phthalate (DEHP) and bisphenol A (BPA) into the aqueous phase. The microbial community, especially autotrophic bacteria such as Cyanobacteria, showed a negative correlation with the additives released from MPs. The inhibition of autotrophs promoted CO2 emissions. Meanwhile, MPs stimulated microbial metabolic pathways such as the tricarboxylic acid (TCA) cycle to accelerate the DOM biodegradation process, and then the transformed DOM presented low bioavailability, high stability, and aromaticity. Our findings highlight an urgent need for chemodiversity and biodiversity surveys to assess ecological risks from MP pollution and the impact of MPs on the carbon cycle.

Bisphenol A and di-ethylhexyl phthalate analysis in gallon water distributed in Makassar

Bisphenol A (BPA) and Di-Ethylhexyl Phthalate (DEHP) are chemical compounds that are used as raw materials for making disposable bottles or PET, including gallons. BPA can migrate into food or drink if the temperature is raised due to heating processes. This research aimed to identify BPA and DEHP compounds in various brands of gallon water distributed in Makassar and the effect of sun exposure towards BPA and DEHP migration. The sampling method was done based on an early analysis from field survey data in the location that represents all gallon water refills distributed in Makassar. There were 4 selected samples from 2 most marketed brands of gallon water refill. Research method included sample preparation with two different treatments, namely with exposure and without exposure to sunlight by letting them settle inside and outside the room for 6 days, afterwards, BPA and DEHP were analyzed using Gas Chromatography - Mass Spectrometry (GC-MS). The results of the study show that in various brands gallon water packages, both with sun exposure or without, no BPA and DEHP compounds were detected.

Qualitative Assessment of Off-Gassing of Compounds from Field-Contaminated Firefighter Jackets with Varied Air Exposure Time Intervals Using Headspace GC-MS.

Firefighters are exposed to a complex mix of volatile and semi-volatile compounds from burning construction materials, consumer products, and other elements during fire suppression and rescue. These compounds can be absorbed onto the gear worn by firefighters and, depending on their volatility, can be released from the gear under different conditions. Few studies have focused on the off-gassing of toxic compounds from firefighters' gear, particularly in terms of qualitative analysis methods. This study introduces a novel qualitative analysis method using headspace gas chromatography-mass spectrometry (HS-GC-MS) to assess off-gassing from field-contaminated jackets at regular intervals. Our findings show that certain compounds, such as acetic acid and di-ethyl-hexyl-phthalate (DEHP), remained present even after the gear were allowed to air out for 48 h. The persistent off-gassing of chemicals, even under ambient conditions, raises concerns about potential hazards that could pose risks for personnel in the vicinity of contaminated gear, including inside fire stations. The implications of these findings extend beyond fire stations and may have significant public health implications for firefighters who are repeatedly exposed to these compounds over time.

A survey of phthalates in flavored olive oils from Turkey

Phthalates are organic contaminants that are used as plasticizers in many plastic food packaging materials. Because of their lipophilic character, oils are the primary source of human exposure to phthalates. In this study, the presence of five phthalate esters; diethylhexyl phthalate (DEHP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), diisononyl phthalate (DINP) and diisodecyl phthalate (DIDP) in olive oils flavored with different materials and marketed in Turkey in 2020 was determined. The samples included BBP, DINP, DIDP at lower concentrations than their LOQ. DEHP was the most abundant phthalate in all samples at varying concentrations between < LOQ to 1.81 mg/kg. The highest amount of DEHP was found in the oil sample flavored with bergamot (1.81 mg/kg). DBP was detected in 9 of the 25 samples at concentrations from 0.11 to 0.27 mg/kg.

Exposure to phthalates and DiNCH among preschool children in Sweden: Urinary metabolite concentrations and predictors of exposure

Several plasticizing chemicals induce endocrine disrupting effects in humans, and the indoor environment is suggested to be a source of exposure. As children are particularly vulnerable to the effects from exposure to endocrine disrupting chemicals (EDCs), it is essential to monitor exposure to EDCs such as phthalates and non-phthalate plasticizers in indoor environments intended for use by children. The aim of this study was to assess everyday plasticizer exposure among preschool-aged children in Sweden by measuring urinary plasticizer metabolite concentrations. In addition, it was investigated whether the concentrations would be altered as a result of the children spending part of the day at preschool, in comparison with weekend exposure, when they may spend more time in home environments or engage in various weekend and leisure activities. For this purpose, fourteen metabolites from eight phthalates (di-ethylhexyl phthalate, DEHP; di-n-butyl phthalate, DnBP; di-isobutyl phthalate, DiBP; butyl-benzyl phthalate, BBzP; di-iso-nonyl phthalate, DiNP; di-propylheptyl phthalate, DPHP; di-iso-decyl phthalate, DiDP; and di-ethyl phthalate, DEP) and one non-phthalate plasticizer (di-isononyl cyclohexane 1,2-dicarboxylate, DiNCH) were measured in 206 urine samples collected at four occasions, i.e. twice during the winter and twice during the spring from 54 children (mean5.1 years, SD 0.94) enrolled at eight preschools in Sweden. A detection frequency (DF) of 99.9% for the 14 metabolites indicates a widespread exposure to plasticizers among children in Sweden. Compared to previous Swedish and international studies performed during approximately the same time period, high urinary concentrations of monobenzyl phthalate (MBzP), a metabolite from the strictly regulated BBzP, were measured in this study (median 17ng/mL). Overall, high urinary phthalate metabolite concentrations were observed in this study compared to the US CDC-NHANES from the same time period and similar age-group. Compared to European studies, however, similar concentrations were observed for most metabolites and the urinary concentrations from few participating children exceeded the human biomonitoring guidance values (HBM-GV) for children. After days with preschool attendance, lower urinary concentrations of metabolites originating from DEP and phthalates that are strictly regulated within the EU REACH legislation (DEHP, DnBP, and DiBP) and higher concentrations of metabolites originating from DiNP, DPHP, and DiDP, i.e. less or non-regulated phthalates were found compared the urinary concentrations of these metabolites in weekends. This may indicate that factors in the indoor environment itself are important for the extent of the plasticizer exposure. All the analyzed metabolites were measured in lower concentrations in urine collected from children attending preschools built or renovated after the year 2000, while no seasonal differences were observed in this study.

Effects of cadmium and diethylhexyl phthalate on skin microbiota of Rana chinensis tadpoles.

Skin microbiotas play a crucial role in the health, homeostasis, and immune function of amphibians. The contaminants in water could affect the structure and composition of microbial communities. The effects of coexisting pollutants on frogs cannot be adequately explained by a single exposure due to the coexistence of Cd and DEHP in the environment. Following exposure to Cd and/or DEHP, we examined the histological characteristics of Rana chensinensis tadpoles. We also used the 16S rRNA gene sequencing technique to assess the relative abundance of skin microbial communities among tadpoles from each treatment group. Our findings indicate that R. chensinensis' skin experienced some degree of injury due to exposure to Cd and DEHP, which led to the imbalance of their skin microbial community homeostasis and thus interfered with the normal trial status of the host. That may eventually lead to the decline of the amphibian population.

Co-occurrence of macroplastics, microplastics, and legacy and emerging plasticisers in UK soils

Despite a theoretical link between plastic and plasticiser occurrence in the terrestrial environment, there are few empirical studies of the relationship between these contaminants in soils. We carried out a field study to assess the co-occurrence of plastic waste, and legacy and emerging plasticisers in UK soils (n = 19) from various land uses (woodlands, urban roadsides, urban parklands, landfill-associated). Surface plastics and soil microplastics were quantified and characterised using ATR-FTIR and μ-FTIR. Eight legacy (phthalate) and three emerging (adipate, citrate, trimellitate) plasticisers were quantified using GC–MS. Surface plastics were found at higher prevalence at landfill-associated and urban roadside sites, with levels significantly (2 orders of magnitude) greater than in woodlands. Microplastics were detected in landfill-associated (mean 12.3 particles g−1 dw), urban roadside (17.3 particles g−1 dw) and urban parkland (15.7 particles g−1 dw) soils, but not in woodland soils. The most commonly detected polymers were polyethene, polypropene and polystyrene. Mean ∑plasticiser concentration in urban roadside soils (3111 ng g−1 dw) was significantly higher than in woodlands (134 ng g−1 dw). No significant difference was found between landfill-associated (318 ng g−1 dw) and urban parkland (193 ng g−1 dw) soils and woodlands. Di-n-butyl phthalate (94.7% detection frequency) and the emerging plasticiser trioctyl trimellitate (89.5%) were the most commonly detected plasticisers, with diethylhexyl phthalate (493 ng g−1 dw) and di-iso-decyl phthalate (96.7 ng g−1 dw) present at the highest concentrations. ∑plasticiser concentrations were significantly correlated with surface plastic (R2 = 0.23), but not with soil microplastic concentrations. Whilst plastic litter seems a fundamental source of plasticisers in soils, mechanisms such as airborne transport from source areas may be as important. Based on the data from this study, phthalates remain the dominant plasticisers in soils, but emerging plasticisers are already widespread, as reflected by their presence in all land uses studied.

Differential pulse voltammetric assessment of phthalate molecular blocking effect on the copper electrode modified by multi-walled carbon nanotubes: Statistical optimization by Box-Behnken experimental design

This research not only assesses the phthalate molecular blocking effect on differential pulse voltammetric nanosensor, but also qualifies phthalate blockers at too low concentrations. To achieve these goals, the copper surface is modified by a two-ingredient paste containing electroencephalographic gel (EEG) and multi-walled carbon nanotubes (MWCNTs). The Fe2+/Fe3+ couple was chosen as a voltammetric signal generator. Di-buthyl phthalate (DBP), di-methyl phthalate (DMP), diethyl hexyl phthalate (DEHP) and dicyclo hexyl (DCHP) phthalate were assessed to block the surface of fabricated nanosensor. The Box-Behnken design (BBD) was used to optimize the experimental major parameters; Fe2+ and supporting electrolyte (KCl) concentrations, pH and MWCNTs/EEG ratio. The phthalate molecular blocker cuts the Fe2+ oxidation signal because of holding Fe2+ ions back from the surface of the nanosensor. The optimum conditions were obtained as CFe2+= 402 µM, CKCl = 0.13 M, pH = 8.2 and MWCNTs/EEG ratio = 0.09. The field emission scanning electron microscopy (FESEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer–Emmett–Teller (BET) porosity analysis, differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were employed for evidence giving and gathering. The obtained results confirmed the molecular blocking effect of phthalates; and an accepted linear relationship between signal cutback and blocker concentration was observed. The limit of detection (LOD) and limit of quantitation (LOQ) were equal to 0.004–0.009 µgL−1 and 0.01–0.03 µgL−1, respectively. Finally, the fabricated nanosensor was successfully utilized in aqueous real sample analyses, and satisfactory results were obtained.

Long-term DEHP/MEHP exposure promotes colorectal cancer stemness associated with glycosylation alterations

Plasticizers are considered as environmental pollution released from medical devices and increased potential oncogenic risks in clinical therapy. Our previous studies have shown that long-term exposure to di-ethylhexyl phthalate (DEHP)/mono-ethylhexyl phthalate (MEHP) promotes chemotherapeutic drug resistance in colorectal cancer. In this study, we investigated the alteration of glycosylation in colorectal cancer following long-term plasticizers exposure. First, we determined the profiles of cell surface N-glycomes by using mass spectrometry and found out the alterations of α2,8-linkages glycans. Next, we analyzed the correlation between serum DEHP/MEHP levels and ST8SIA6 expression from matched tissues in total 110 colorectal cancer patients. Moreover, clinical specimens and TCGA database were used to analyze the expression of ST8SIA6 in advanced stage of cancer. Finally, we showed that ST8SIA6 regulated stemness in vitro and in vivo. Our results revealed long-term DEHP/MEHP exposure significantly caused cancer patients with poorer survival outcome and attenuated the expression of ST8SIA6 in cancer cells and tissue samples. As expected, silencing of ST8SIA6 promoted cancer stemness and tumorigenicity by upregulating stemness-associated proteins. In addition, the cell viability assay showed enhanced drug resistance in ST8SIA6 silencing cells treated with irinotecan. Besides, ST8SIA6 was downregulated in the advanced stage and positively correlated with tumor recurrence in colorectal cancer. Our results imply that ST8SIA6 potentially plays an important role in oncogenic effects with long-term phthalates exposure.

Human biomonitoring guidance values (HBM-GVs) for priority substances under the HBM4EU initiative - New values derivation for deltamethrin and cyfluthrin and overall results.

The European Initiative HBM4EU aimed to further establish human biomonitoring across Europe as an important tool for determining population exposure to chemicals and as part of health-related risk assessments, thus making it applicable for policy advice. Not only should analytical methods and survey design be harmonized and quality assured, but also the evaluation of human biomonitoring data. For the health-related interpretation of the data within HBM4EU, a strategy for deriving health-based human biomonitoring guidance values (HBM-GVs) for both the general population and workers was agreed on. On this basis, HBM-GVs for exposure biomarkers of 1,2-cyclohexane dicarboxylic acid diisononyl ester (DINCH), phthalates (diethyl hexyl phthalate (DEHP), di-n-butyl phthalate (DnBP), diisobutyl phthalate (DiBP), butyl benzyl phthalate (BBzP), and bis-(2-propylheptyl) phthalate (DPHP)), bisphenols A and S, pyrethroids (deltamethrin and cyfluthrin), solvents (1-methyl-2-pyrrolidone (NMP), 1-ethylpyrrolidin-2-one (NEP), N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAC)), the heavy metal cadmium and the mycotoxin deoxynivalenol (DON) were developed and assigned a level of confidence. The approach to HBM-GV derivations, results, and limitations in data interpretation with special focus on the pyrethroids are presented in this paper.

New insight into long-term effects of phthalates microplastics in developing zebrafish: Evidence from genomic alteration and organ development

The plasticizer leaches from the microplastics are one of the significant concerns related to plastic pollution. These plasticizers are known to be endocrine disrupters; however, little is known about their long-term effect on the development of aquatic vertebrates. Hence, the present study has been conducted to provide a holistic understanding of the effect of the three most common plasticizers, dibutyl phthalate (DBP), diethyl phthalate (DEP), and di-ethylhexyl phthalate (DEHP) leaching out from the microplastics in zebrafish development. Zebrafish larvae were exposed to different phthalates at different concentrations. The phthalates have shown significantly higher mortality and morphological changes in the larva upon exposure compared to the control. A significant change in the genes related to cardiovascular development (krit1, fbn2b), dorsoventral axis development (chrd, smad5), tail formation (pkd2, wnt3a, wnt8a), and floorplate development (foxa2) were also observed under the effects of the phthalates in comparison to control.

Gas-Particle Partitioning of Semivolatile Organic Compounds in a Residence: Influence of Particles from Candles, Cooking, and Outdoors.

Semivolatile organic compounds (SVOCs) represent an important class of indoor pollutants. The partitioning of SVOCs between airborne particles and the adjacent air influences human exposure and uptake. Presently, little direct experimental evidence exists about the influence of indoor particle pollution on the gas-particle phase partitioning of indoor SVOCs. In this study, we present time-resolved gas- and particle-phase distribution data for indoor SVOCs in a normally occupied residence using semivolatile thermal desorption aerosol gas chromatography. Although SVOCs in indoor air are found mostly in the gas phase, we show that indoor particles from cooking, candle use, and outdoor particle infiltration strongly affect the gas-particle phase distribution of specific indoor SVOCs. From gas- and particle-phase measurements of SVOCs spanning a range of chemical functionalities (alkanes, alcohols, alkanoic acids, and phthalates) and volatilities (vapor pressures from 10-13 to 10-4 atm), we find that the chemical composition of the airborne particles influences the partitioning of individual SVOC species. During candle burning, the enhanced partitioning of gas-phase SVOCs to indoor particles not only affects the particle composition but also enhances surface off-gassing, thereby increasing the total airborne concentration of specific SVOCs, including diethylhexyl phthalate.

DEHP mediates drug resistance by metabolic reprogramming in colorectal cancer cells

Long-term exposure to diethylhexyl phthalate (DEHP), an endocrine-disrupting chemical (EDCs) and plasticizer widely used in consumer products, has been reported to be significantly positively correlated with increased risks of different human diseases, including various cancers, while the potential effect of DEHP on colorectal cancer progression was little studied. In the present study, we showed that DEHP could trigger the metabolic reprogramming of colorectal cancer cells, promote cell growth and decrease fluorouracil (5-FU) sensitivity. Mechanistic studies indicated that DEHP could reduce glycolysis activity and increase oxidative phosphorylation (OXPHOS) in SW620 cells. In addition, in vivo experiments showed that DEHP promoted tumorigenic progression and decreased survival time in mice. Collectively, our findings suggest that DEHP may be a potent risk factor for colorectal cancer development.

Leaching rate of Diethylhexyl Phthalate (DEHP) from PVC containers with IV administrated lipid nanoparticle formulations

Leaching rate of Diethylhexyl Phthalate (DEHP) from PVC containers with IV administrated lipid nanoparticle formulations

PHTHALATE ESTERS (PLASTICIZERS) IN THE UROPYGIAL GLAND AND THEIR RELATIONSHIP TO PLASTICS INGESTION IN SEABIRDS ALONG THE COAST OF ESPÍRITO SANTO, EASTERN BRAZIL.

Plastic ingestion is a problem for seabirds worldwide. In addition to direct health effects such as obstruction or perforation of the gastrointestinal tract, plastic ingestion can also lead to indirect health effects through the release of chemicals that may be absorbed and cause systemic and chronic toxicity. Among chemicals that can be released by plastics are phthalate esters, a group of chemicals widely used as plasticizers or additives to change the physical characteristics of plastics. In this study, three phthalate esters, dimethyl phthalate (DMP), dibuthyl phthalate (DBP), and diethylhexyl phthalate (DEHP), were quantified in the uropygial gland of 48 seabirds from 16 species collected ashore in a tropical region, the coast of Espírito Santo, Eastern Brazil. Including trace levels, DMP was detected in 16 birds (33%) from 10 species, with an average concentration of 0.014 ± 0.005 ng/µl (mean ± SD for individuals with concentrations above the practical level of detection of 0.01 ng/µl). DBP was detected in 15 birds (31%) from 11 species, with an average concentration of 0.049 ± 0.032 ng/µl. DEHP was detected in 21 birds (44%) from 11 species, with an average concentration of 0.115 ± 0.105 ng/µl. DMP concentration in the uropygial gland was positively associated with the presence, number, and mass of plastic items in the upper digestive tract. However, no such relationship was noted for DBP nor DEHP, suggesting the concentration of phthalate compounds in the uropygial gland might not always serve as a reliable proxy for plastic ingestion. In spite of relatively high frequencies of detection, the low concentrations of phthalates detected in this study suggest levels of exposure below known toxicity thresholds. Further studies on the potential adverse effects of phthalate exposure in seabirds are necessary, especially on the reproductive development of embryos and chicks.

Understanding plasticiser leaching from polystyrene microplastics.

Plastic pollution in our oceans is of growing concern particularly due to the presence of toxic additives, such as plasticisers. Therefore, this work aims to develop a comprehensive understanding of the leaching properties of plasticisers from microplastics. This work investigates the leaching of phthalate acid ester (dioctyl terephthalate (DEHT) and diethylhexyl phthalate (DEHP)) and diphenol (bisphenol A (BPA) and bisphenol S (BPS)) plasticisers from polystyrene (PS) microplastics (mean diameter = 136 μm to 1.4 mm) under controlled aqueous conditions (temperature, agitation, pH and salinity). The leaching behaviours of plasticised polymers were quantified using gel permeation chromatography, high performance liquid chromatography and thermal gravimetric analysis, and the particle's plasticisation characterised using differential scanning calorimetry. Leaching rates of phthalate acid ester and diphenol plasticisers were modelled using a diffusion and boundary layer model, whereby these behaviours varied depending on their plasticisation efficiency of PS, the size of the microplastic particle and the surrounding abiotic conditions. Leaching behaviours of DEHT and DEHP were strongly influenced by the microplastic-surface water boundary layer properties, thus wave action (i.e., water agitation) increased the leaching rate of these plasticiser up to 66 % over 21-days, whereas BPA and BPS plasticisers displayed temperature- and size-dependent leaching and were limited by molecular diffusion throughout the bulk polymer (i.e., the microplastic). This information will improve predictions of plasticiser concentration (both that remain in the plastic and released into the surrounding water) at specific time points during the lifetime of a plastic, ultimately ensuring greater accuracy in the assessment of toxicity responses and environmental water quality.

A Case-Control Study on the Effects of Plasticizers Exposure on Male Fertility.

Male infertility is a serious concern for public health, and the possible role of exposure to plasticizers such as phthalates and bisphenol A in contributing to the condition is widely debated. We have herein enrolled 155 infertility cases attending an infertility center and 211 controls (fathers of a spontaneously conceived newborn) to investigate this issue. The urinary levels of seven phthalates and BPA were analyzed through HPLC/MS/MS. All data were statistically elaborated considering information about clinical situation, life habits, occupational activity, and, for cases, semen parameters (volume, sperm concentration, total count of spermatozoa, and sperm motility). Results showed significantly higher urinary concentrations for all the phthalates in cases compared to controls, except for monoethylphthalate and BPA. In total, 90.07% of cases had sperm motility lower than the WHO reference value (2010), while 53.69%, 46.31%, and 16.56% had sperm total number, concentration, and volume, respectively, out of the reference range. Regarding the possible source of exposure, the use of scents seems to be a significant source of DEP (diethylphthalate). When considering occupational settings, industrial workers, dental technicians, artisans, and farmers using chemicals showed higher risk (OR = 2.766, 95% CI 1.236-6.185), particularly in relation to DnBP (di-n-butyl phthalate) and DEHP (di-ethyl-hexyl phthalate) exposure. No clear quantitative correlation between specific plasticizers and sperm parameters could be demonstrated but these findings call for future studies about the risks associated with exposure to their mixture.

Mechanism involved in cell death induced by DEHP (Di-ethylhexyl phthalate) on primary brain cells from Zebrafish (Danio rerio)

Human and ecological exposure to chemical contaminants continue to increase given anthropogenic activities and sources. Phthalates are among the most persistent toxic chemicals found in aquatic systems. Phthalates belong to a family of chemical compounds that are heavily used in global manufacturing, distinguished for being able to provide durability and elasticity to plastic products, with poor water solubility and low evaporation. In terms of health impact, these compounds have been shown to breach the placental barrier having effect on human development and neurodegeneration. The main purpose of our study has been to assess the neurotoxicity of phthalates implementing the zebrafish (Danio rerio) model to determine the cell death induction of DEHP on brain cells. For many years, the zebrafish embryonic model has been used to study vertebrate development. Our study, in contrast, used adult zebrafish to resemble mature species that can be continuously exposed to low concentrations of DEHP. To assess the neurotoxicity, brain tissue from zebrafish was extracted via dissection, and primary neural cells dissociated to obtain primary cell subcultures. The neural cells where subsequently exposed to DEHP (Di-ethylhexyl phthalate) at concentrations from 10µM to 100µM for 48 hours to observe cell growth inhibition (GI50). The results indicate neural cell death at a GI50 of 62.9 µM. Apoptosis induction, caspase activation, mitochondrial membrane damage as well as autophagy cell death were analyzed to identify DEHP cell death mechanism at the GI50 concentration. In conclusion, this study clearly demonstrated that DEHP can induce apoptosis cell death on zebrafish neural brain cells in culture through the activation of an intrinsic apoptotic pathways with caspases 3 and 7 activation as well as autophagic pathway and mitochondrial damage. The presence of phthalates as well as other chemical contaminants on aquatic environments needs to be earnestly controlled in order to reduce neurotoxicity to aquatic species as well as human.

Determination of phthalates in bottled waters using solid-phase microextraction and gas chromatography tandem mass spectrometry.

Phthalates are synthetic chemicals widely used, mainly as plasticizers, which are ubiquitous and recognized as endocrine-disrupting chemicals. For investigation of phthalate residues leached from PET bottles into drinking water, a simple and sensitive method was developed, validated and applied to a series of real samples. Solid-phase microextraction (SPME) was used in direct immersion mode for concentration of phthalate traces from 10mL of each water sample. Four commercially available SPME fibers were tested and compared, while six dialkyl phthalates were investigated: dimethyl phthalate (DMP), diethyl phthalate (DEP), diisopropyl phthalate (DiPP), diisobutyl phthalate (DiBP), di-n-butyl phthalate (DnBP) and di-ethylhexyl phthalate (DEHP). The extracted phthalic acid esters were separated and quantified by gas chromatography hyphenated with tandem mass spectrometry (GC-MS/MS) and a detection method based on multiple reaction monitoring (MRM) mode was fully developed, optimized and validated. The fiber which showed the highest ability for extraction of phthalates was DVB/CAR/PDMS which combines a liquid polymeric coating (polydimethyl siloxane and divinylbenzene) with a carboxen porous sorbent layer. The obtained limit of detection was in the range between 0.3 and 2.6ngmL-1. Thus, this fiber was used for extraction of phthalates from twelve commercial PET bottled water samples. All investigated water brands showed the presence of two to six phthalates at concentrations between 6.3 and 112.2ngmL-1. The highest level was observed for DnBP, followed by DEHP, DiBP, DMP, DEP and DiPP.

Continuous treatment of diethyl hexyl and dibutyl phthalates by fixed-bed reactor: Comparison of two esterase bionanocomposites

The removal of Diethyl hexyl phthalate (DEHP) and Dibutyl phthalate (DBP) is of great importance due to their potential adverse effects on the environment and human health. In this study, two bionanocomposites prepared by immobilization of Bacillus subtilis esterase by crosslinking to halloysite and supported in chitosan and alginate beads were studied and proposed as a green approach. The esterase immobilization was confirmed by physical–chemical characterization. Bionanocomposite using chitosan showed the best degradation levels in batch tests attaining complete degradation of DBP and around 90% of DEHP. To determine the operational stability and efficiency of the system, two fixed bed reactors filled with both bionanocomposites were carried out operating in continuous mode. Chitosan based bionanocomposite showed the best performance being able to completely remove DBP and more than 85% of DEHP at the different flowrates. These results proved the potential of these synthesized bionanocomposites to effectively remove Phthalic Acid Esters.