Tris 2-ethylhexyl Phosphate Research Articles

Organophosphate esters in reservoir water from a metropolitan city in the Guangdong-Hong Kong-Macao Greater Bay Area, China, and their ecological risk

Organophosphate esters (OPEs) are emerging flame retardants widely used in products such as furniture, electronic equipment, construction, and plastics. It has been demonstrated that OPEs are harmful to humans and aquatic organisms, thus posing a threat to ecosystems. Considering that reservoirs are critical sources of drinking water for residents in Southern China, this study quantified nine OPEs in water samples collected from 29 reservoirs and their tributaries. The temporal and spatial distributions of OPEs were analyzed and their ecological risks were assessed. The results showed an extensive presence of OPEs in reservoirs, and the median concentration of Σ9OPEs was much higher in the dry season (65.3 ng/L) than in the wet season (21.3 ng/L). Triisobutyl phosphate (TiBP) (median: 5.24 ng/L) and tris(2-ethylhexyl) phosphate (TEHP) (median: 10.8 ng/L) dominated in the wet and dry seasons, respectively. Other OPEs varied considerably in concentrations over time, related to their physical and chemical properties, environmental factors (e.g., precipitation and temperature), and varied applications. Furthermore, the significant correlations of individual OPEs suggest their shared utilization, emission sources, and environmental behaviors. Spatially, there was no significant difference (P > 0.05) among the Σ9OPEs concentrations in water samples from different sites (inlet, reservoir, outlet, and tributary) of the reservoirs. Additionally, the concentrations of OPEs in reservoir water samples could be linked to industrial development, economic conditions, and population density. OPEs in the reservoir pose low ecological risks (RQ < 0.1), except for EDHPP and TEHP, which present median ecological risks (RQ = 0.54 and 0.38, respectively). Future studies could investigate more OPEs and their joint effects with other organic pollutants, as well as survey the chemical reactions and degradation pathways of OPEs in different environmental matrices to assess their potential ecotoxicity more comprehensively.

Metabolic perturbation and oxidative damage induced by tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) and tris(2-ethylhexyl) phosphate (TEHP) on Escherichia coli through integrative analyses of metabolome

Organophosphate esters (OPEs) are one of the emerging environmental threats, causing the hazard to ecosystem safety and human health. Yet, the toxic effects and metabolic response mechanism after Escherichia coli (E.coli) exposed to TDCIPP and TEHP is inconclusive. Herein, the levels of SOD and CAT were elevated in a concentration-dependent manner, accompanied with the increase of MDA contents, signifying the activation of antioxidant response and occurrence of lipid peroxidation. Oxidative damage mediated by excessive accumulation of ROS decreased membrane potential and inhibited membrane protein synthesis, causing membrane protein dysfunction. Integrative analyses of GC-MS and LC-MS based metabolomics evinced that significant perturbation to the carbohydrate metabolism, nucleotide metabolism, lipids metabolism, amino acid metabolism, organic acids metabolism were induced following exposure to TDCIPP and TEHP in E.coli, resulting in metabolic reprogramming. Additionally, metabolites including PE(16:1(5Z)/15:0), PA(17:0/15:1(9Z)), PC(20:2(11Z,14Z)/12:0), LysoPC(18:3(6Z,9Z,12Z)/0:0) were significantly upregulated, manifesting that cell membrane protective molecule was afforded by these differential metabolites to improve permeability and fluidity. Overall, current findings generate new insights into the molecular toxicity mechanism by which E.coli respond to TDCIPP and TEHP stress and supply valuable information for potential ecological risks of OPEs on aquatic ecosystems.

Fugacity- and biotransformation-based mechanistic insights into the trophic transfer of organophosphate flame retardants in a subtropical coastal food web from the Northern Beibu Gulf of China

The bioaccumulation and trophic transfer of organophosphate flame retardants (OPFRs) in marine ecosystems have attracted great attention in recent research, but our understanding of the trophic transfer mechanisms involved is limited. In this study, we investigated the trophodynamics of OPFRs and their metabolites in a subtropical coastal food web collected from the northern Beibu Gulf, China, and characterized their trophodynamics using fugacity- and biotransformation-based approaches. Eleven OPFRs and all seven metabolites were simultaneously quantified in the shellfish, crustacean, pelagic fish, and benthic fish samples, with total concentrations ranging from 164 to 4.11 × 104 and 4.56–4.28 × 103 ng/g lipid weight, respectively. Significant biomagnification was observed only for tris (phenyl) phosphate (TPHP) and tris (2-ethylhexyl) phosphate (TEHP), while other compounds except for tris(2-chloroethyl) phosphate (TCEP) displayed biomagnification trends based on Monte Carlo simulations. Using a fugacity-based approach to normalize the accumulation of OPFRs in biota to their relative biological phase composition, storage lipid is the predominant biological phase for the mass distribution of 2-ethylhexyl diphenyl phosphate (EHDPHP) and TPHP. The water content and structure protein are equally important for TCEP, whereas lipid and structure protein are the two most important phases for other OPFRs. The mass distribution of these OPFRs along with TLs can explain their trophodynamics in the food web. The organophosphate diesters (as OPFR metabolites) also displayed biomagnification trends based on bootstrapped estimation. The correlation analysis and Korganism-water results jointly suggested the metabolites accumulation in high-TL organisms was related to biotransformation processes. The metabolite-backtracked trophic magnification factors for tri-n‑butyl phosphate (TNBP) and TPHP were both greater than the values that accounted for only the parent compounds. This study highlights the incorporation of fugacity and biotransformation analysis to characterize the trophodynamic processes of OPFRs and other emerging pollutants in food webs.

Enhancing cellulose acetate film with green plasticizers for improved performance, biodegradability, and migration study into a food simulant

Cellulose acetate (CA) is a synthetic compound obtained by acetylation of cellulose. It is widely used for various applications, including food packaging films. However, CA is very rigid due to the β-d-glycose ring in its main chain, and the presence of many hydrogen bonds between the hydroxyl groups, which limits the extent of its application. Therefore, plasticizers are generally used to provide flexibility particularly when used for packaging. The migration of plasticizers from packaging materials to packaged food can pose a risk to human health, particularly when the plasticizers present some levels of toxicity. The objective of this research is to compare the effect of widely used plasticizers glycerol, tris (2-ethylhexyl) phosphate (TEHP) and rosemary essential oil on the properties of cellulose acetate films for food packaging. Cellulose acetate films were prepared via solvent casting method followed by plasticizing. The films prepared were characterized using infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-Ray diffraction analysis (XRD) and others analysis. The results show that rosemary essential oil has the lowest migration rate to food simulants. Rosemary can play dual roles, a plasticizer by improving mechanical properties and an active agent (antioxidant, antimicrobial, and UV protector, and promotor of biodegradability). The results show the potential of rosemary essential oil as an additive for application in food packaging.

Investigating the mechanism of Au(III) transport using a polymer inclusion membrane with dibutyl carbitol as a carrier

In this article, firstly, the separation and transfer of Au(III) from gold chloride solution was investigated using a polymer inclusion membrane (PIM) system containing dibutyl carbitol (DBC) as carrier molecules, dioctyl phthalate (DOP), bis(2-ethyl hexyl) adipate (dioctyl adipate) (DOA) and tris (2-ethyl hexyl) phosphate (T2EHP) as plasticizers and high molecular weight polyvinyl chloride (PVC) as the base polymer. Fourier transform infrared spectroscopy (FT-IR), and scanning electron microscope (SEM) were used to identify PIMs. Kinetic studies featuring a two-step reaction, with the first step being reversible, were conducted across various sections to investigate the processes of extraction, stripping, and transport. The effects of different stripping agents such as water, HCl, thiourea, sodium thiosulfate, and oxalic acid was investigated, and the best results were obtained with thiourea. Also, the mechanisms of Au(III) extraction and transport were studied. Under the conditions of source solution, tetrachloroaurate anionic complex AuCl4− with protonated DBC (ROR2OHM+) was extracted by ion solvation mechanism. The validity of the proposed extraction mechanism was confirmed through the use of nuclear magnetic resonance (1H NMR) spectroscopy. In order to make the membrane with the best composition and the highest efficiency, the effect of weight percentage of the carrier and plasticizer was investigated. There was an optimal value for the weight percentage of plasticizer (10–20% by weight) and carrier (40%), in which the highest flux and permeability in the membrane occurred. The effect of the viscosity of different plasticizers (DOP, DOA, and T2EHP) on the Au(III) flux was also investigated. It was found that the flux increases linearly with the reduction of plasticizer viscosity. Effect of membrane thickness on the permeability, initial flux, and efficiency of Au(III) transfer, were conducted with thickness of 120, 80, 45, and 30 μm. By reducing the thickness of the membrane, the transfer flux, permeability and percent of Au(III) transport, were improved from 12.9 × 10−3mh−1, 45.3 × 10−7molm−2s−1 and 18.2% to 26.4 × 10−3mh−1, 83.5 × 10−7molm−2s−1 and 37.3%, respectively. According to the results, a membrane with a combination of PVC:DBC:D2EHP with a weight percentage ratio of 50:40:10 with a thickness of 30 μm was suggested. Optimized results with the proposed membrane were obtained to be: extraction rate constant of 1.43 h−1, extraction percent of 99.1%, stripping rate constant of 37.5 × 10−4h−1, stripping percent of 40.9%, and permeability of 27.0 × 10−3mh−1, initial flux of 82.1 × 10−7molm−2s−1.

Pollution characteristics and risk assessment of organophosphate esters (OPEs) in typical industrial parks in Southwest China.

As alternative substances of PBDEs, organophosphate esters (OPEs), an emerging organic pollutant, were increasingly produced and used in many kinds of industries and consumer products. However, OPEs also have various adverse toxic effects. Information on the pollution levels and exposure to OPEs in related industries is still limited. This study presented data on OPE contamination in the soil, leaf, and river water samples from seven typical industrial parks in Southwest China. Total concentration of seven OPEs (Σ7OPE) including tri-n-butyl phosphate (TnBP), tris-(2-ethylhexyl) phosphate (TEHP), tris-(2-butoxyethyl) phosphate (TBEP), tris-(2-carboxyethyl) phosphine (TCEP), triphenyl phosphate (TPhP), tris-(1,3-dichloro-2-propyl) ester (TDCPP), and tris-(chlorisopropyl) phosphate (TCPP) in the soil samples (36.2 ~ 219.7 ng/g) and the surrounding river water samples (118.9 ~ 287.7 ng/L) were mostly lower than those in other studies, while the Σ7OPE level in the leaves (2053.3 ~ 8152.7 ng/g) was relatively high. There were significant differences in the concentration and distribution of OPEs in the surrounding environment of different industrial parks. TDCPP, TnBP, and TCPP could be used as the characteristic compound in soil samples from auto industrial park, river samples from shoe making industrial park, and leaf samples from logistics park, respectively. The parameter m (the content ratio of chlorinated OPEs to alkyl OPEs) was suggested to distinguish the types of industrial park preliminary. When m ≥ 1, it mainly refers to heavy industries sources such as automobiles, electronics, and machinery, etc. When m<1, it mainly for the light industrial sources such as textile industry, transportation services, and resources processing, etc. For logistics park, furniture park and Wuhou comprehensive industrial park, the volatilization of materials was the main sources of OPEs in the surrounding environment, while more effort was required to strengthen the pollution control and management of the waste water and soil in the pharmacy industrial park, shoe making industrial park and auto industrial park. Risk assessment showed that there was a negligible non-cancer and carcinogenic risk in the soil, while high attention should be paid to the non-cancer risk for children.

Organophosphate ester additives and microplastics in benthic compartments from the Loire estuary (French Atlantic coast)

We report the first empirical confirmation of the co-occurrence of organophosphate esters (OPEs) additives and microplastics (MPs) in benthic compartments from the Loire estuary. Higher median concentrations of MPs (3387 items/kg dw), ∑13tri-OPEs (12.0 ng/g dw) and ∑4di-OPEs (0.7 ng/g dw) were measured in intertidal sediments with predominance of fine particles, and under higher anthropogenic pressures, with a general lack of seasonality. Contrarily, Scrobicularia plana showed up to 4-fold higher ∑tri-OPE concentrations in summer (reaching 37.0 ng/g dw), and similar spatial distribution. Polyethylene predominated in both compartments. Tris(2-ethylhexyl) phosphate (TEHP), its degradation metabolite (BEHP) and tris-(2-chloro, 1-methylethyl) phosphate (TCIPP) were the most abundant OPEs in sediments, while TCIPP predominated in S. plana. The biota-sediment accumulation factors suggest bioaccumulation potential for chlorinated-OPEs, with higher exposure in summer. No significant correlations were generally found between OPEs and MPs in sediments suggesting a limited role of MPs as in-situ source of OPEs.

Degradation of organophosphate flame retardants by a consortium of bacterial strains isolated from the To Lich river, Hanoi

Organophosphate flame retardants (OPFRs) are degraded by a consortium of 10 bacterial strains isolated from the To Lich river, contaminated with OPFRs. The bacterial consortium is cultured in an A-Cl medium supplemented individually with OPFRs (10 mg/l), resulting in optical density at 600 nm ranging from 1 to 1.5. The consortium of 10 bacterial strains exhibits the ability to degrade tris(2-ethylhexyl) phosphate (TEHP) by 98.5 and 100% after two and three days of cultivation, respectively. Triethyl phosphate (TEP) is also degraded by 76.1 and 100% after two and five days of cultivation, respectively. The degradation efficiency of trimethyl phosphate (TMP), tris(2-chloroethyl) phosphate (TCEP), tris(1,3-dichloro-2-propyl) phosphate (TCDPP), and tributoxy ethyl phosphate (TBEP) is also in the range of 97 to 100% after four days of cultivation. In the experiment adding a mixture of 7 substances in OPFRs at a concentration of 10 mg/l for each compound, only TEHP is completely degraded after six days of cultivation. The degradation efficiency of other OPFRs increases from 93.2 to 100% after six days of cultivation. Comparing the degradation rates of OPFRs in both experiments, the results indicate that the cultures supplemented with each compound individually exhibit a faster degradation rate than when a mixture of OPFRs compounds is added.

Organophosphorus flame retardants and their metabolites in paired human blood and urine

Organophosphorus flame retardants (OPFRs) have been shown to be carcinogenic, neurotoxic, and endocrine disruptive, so it is important to understand the levels of OPFRs in human body as well as the modes of external exposure. In this study, we investigated the levels of 13 OPFRs and 7 phosphodiester metabolites in paired human blood and urine, as well as the influencing factors (region, age and gender), and studied the relationship between OPFRs and oxidative stress by urinary metabolites. We found that the concentrations of triphenyl phosphate (TPhP) and tris-(2-ethylhexyl) phosphate (TEHP) in the blood of urban populations were higher than those of rural populations, and that younger populations suffered higher TPhP and 2-ethylhexyl diphenyl phosphate (EHDPP) exposures than older populations. In addition, we found that tris-(2-chloroethyl) phosphate (TCEP), tributyl phosphate (TnBP), TPhP and EHDPP exposure induced oxidative stress. The results of the internal load principal component analysis indicated that dust ingestion, skin exposure, respiration and dietary intake may be the most important sources of TCEP, tris(2-butoxyethyl) phosphate (TBOEP), tri(2-chloroisopropyl) phosphate (TCIPP) and TEHP, respectively, and dust ingestion and skin exposure may be the main sources of TPhP for humans.

A new approach for cobalt (II) removal from simulated wastewater using electro membrane extraction with a flat sheet supported liquid membrane

The aim of this work was to efficiently remove cobalt (Co) from aqueous solutions by using a novel Electromembrane Extraction (EME) technique. This novel electrochemical cell design featured two distinct glass chambers, incorporating a Supported Liquid Membrane (SLM) composed of a polypropylene flat membrane saturated with 1-octanol and a carrier substance, as well as electrodes constructed from graphite and stainless steel. The investigation covered an exploration of various effective parameters like, carrier type, voltage across the cell, donor solution pH, and the initial Co concentration, with the overarching goal of comprehending their individual effect on Co removal efficiency. Notably, two different carriers, tris(2-ethylhexyl) phosphate (TEHP) and bis(2-ethylhexyl) phosphate (DEHP), were systematically evaluated in combination with 1-octanol. The findings underscored the pivotal role of the cell voltage in significantly enhancing the mass transfer rate of cobalt across the membrane, thereby advancing the effectiveness of the removal process. After a comprehensive optimization process, the optimal operating conditions were established as follows: employing 1-octanol with 1.0 % v/v bis(2-ethylhexyl) phosphate as a carrier, applying a voltage of 60 V, maintaining an initial pH of 5, utilizing an initial cobalt concentration of 15 mg/L, conducting an extraction for 6 h, and employing a stirring rate of 1000 rpm. Remarkably, these conditions led to the attainment of an impressive removal efficiency of 87 %. In stark contrast, when no voltage was applied, the removal efficiency did not surpass 40 %. This underscores the pivotal role of the applied voltage in enhancing the cobalt removal process under the specified conditions.

Suppression of Interphase Dissolution Via Solvent Molecule Tuning for Sodium Metal Batteries.

Solvent molecule tuning is used to alter the redox potentials of solvents or ion-solvent binding energy for high-voltage or low-temperature electrolytes. Herein, an electrolyte design strategy that effectively suppresses solid electrolyte interphase (SEI) dissolution and passivates highly-reactive metallic Na anode via solvent molecule tuning is proposed. With rationally lengthened phosphate backbones with ─CH2 ─ units, the low-solvation tris(2-ethylhexyl) phosphate (TOP) molecule effectively weakens the solvation ability of carbonate-based electrolytes, reduces the free solvent ratio, and enables an anion-enriched primary Na+ ion solvation sheath. The decreased free solvent and compact lower-solubility interphase established in this electrolyte prevent electrodes from continuous SEI dissolution and parasitic reactions at both room temperature (RT) and high temperature (HT). As a result, the Na/Na3 V2 (PO4 )3 cell with the new electrolyte achieves impressive cycling stability of 95.7% capacity retention after 1800 cycles at 25 °C and 62.1% capacity retention after 700 cycles at 60°C. Moreover, the TOPmolecule not only maintains the nonflammable feature of phosphate but also attains higher thermal stability, which endows the electrolyte with high safety and thermal stability. This design concept for electrolytes offers a promising path to long-cycling and high-safetysodium metal batteries.

Zinc (II) removal from simulated wastewater by electro-membrane extraction approach: Adopting an electrolysis cell with a flat sheet supported liquid membrane

The aim of this study is to utilize the electromembrane extraction (EME) system as a manner for effective removal of zinc from aqueous solutions. A novel and distinctive electrochemical cell design was adopted consisting of two glass chambers, a supported liquid membrane (SLM) housing a polypropylene flat membrane infused with 1-octanol and a carrier. Two electrodes were used, a graphite as anode and a stainless steel as cathode. A comprehensive examination of several influential factors including the choice of carrier, the applied voltage magnitude, the initial pH of the donor solution, and the initial concentration of zinc was performed, all in a concerted effort to ascertain their respective impacts on the efficiency of zinc elimination. Two distinct carriers, namely tris(2-ethylhexyl) phosphate (TEHP) and bis(2-ethylhexyl) phosphate (DEHP) were evaluated, in a tandem with utilization of 1-octanol. The results revealed essential role played by the applied voltage in augmenting the rate of mass transfer of zinc across the membrane. The best operating conditions were utilized for 1-octanol enriched with 1.0 vol.% bis(2-ethylhexyl) phosphate as a carrier, applied voltage of 60 V, initial pH of 5, initial zinc concentration of 15 mg L-1, extraction duration of 6 hours, and stirring rate of 1000 rpm. Surprisingly, operating under these meticulously devised conditions culminated in the outstanding removal efficiency of 87.3 %. In comparison with no applied voltage, a substantial enhancement in removal efficiency was observed, trans­cending from a meager 36.67 % to an impressive 87.3 % at 60 V, suggesting thus a tremen­dous potential of EME as an efficacious technique for the elimination of heavy metals.

Tissue distribution and trophic transfer of organophosphate triesters and diesters in three marine mammals of the Liaodong Bay and the Northern Yellow Sea

Tissue (muscle, liver, kidney, lung, and heart) distribution and trophic transfer of organophosphate (OP) triesters and diesters in stranded 10 minke whales, 20 spotted seals and 27 East Asian finless porpoises from the Liaodong Bay and the Northern Yellow Sea were evaluated. The OP triesters and diesters were widely found in the tissues of the three marine mammals and their preys, with mean concentrations ranging from below the limits of detection (LOD) to 4342 μg/kg dry weight (dw) and from below the LOD to 1460 μg/kg dw, respectively. Tissue-specific distribution of the OP triesters or diesters were found in the investigated marine mammals with chemical-specific and species-specific. Log Kow negatively affect the accumulation of OP diesters in the marine mammals (p < 0.05), which related to their accumulation pathway in the tissues. The biological traits of the three marine mammals, body length, gender and age could affect the distribution of several OP triesters or diesters. Yet more concern is that significantly biological magnification was found for bis(2-chloroethyl) phosphate (BCEP) with trophic magnification factor (TMF) of 5.36 and for tris(2-ethylhexyl) phosphate (TEHP)(TMF:2.88) along with the finless porpoise food web. These results considerably contribute to expanding understanding of OP triesters or diesters pollution on the organisms in marine ecosystem.

High-resolution mass spectrometry-based screening and dietary intake assessment of organophosphate esters in foodstuffs from South China

Organophosphate esters (OPEs) are a group of emerging contaminants with widespread environmental occurrence, yet research on their occurrence in foodstuffs is limited. We collected 100 foodstuff samples in South China using a market basket method, and analyzed food extracts for the presence of OPEs and organophosphite antioxidants (OPAs) by suspect and nontarget screening through high-resolution mass spectrometry. Our analysis resulted in the identification of 30 OPEs, comprised of 25 OPEs with a confidence level (CL) of 1 (unequivocal identification using standards) and five OPEs with CL = 2b (probable structure based on diagnostic evidence). Interestingly, 11 of these identified OPEs had not been previously reported in food. No OPA was identified. The occurrence of identified OPEs within the food samples was further investigated. The highest median concentration of OPEs in all food samples was reached by tris(2-chloroisopropyl) phosphate (TCPP) (1.55 ng/g ww, range < 0.74–12.0 ng/g wet weight (ww)). Cereals demonstrated the highest median concentration of the cumulative 30 OPEs. Tris(2-chloroethyl) phosphate (TCEP), TCPP, and triethyl phosphate (TEP) predominantly contributed to OPEs contamination in most food categories. Eight OPEs, namely TEP, tris(2-ethylhexyl) phosphate (TEHP), TCEP, triphenyl phosphate (TPhP), 2-ethylhexyl diphenyl phosphate (EHDPP), bis(2-ethylhexyl) phenyl phosphate (BEHPP), resorcinol bis(diphenyl phosphate) (RDP), and methyl diphenyl phosphate (MDPP) exhibited significantly higher concentrations in the processed group as compared to non-processed group, suggesting that food processing may result in contamination of these OPEs. The median sum of estimated dietary intake (ΣEDI) of all OPEs was determined to be 161 ng/kg body weight/day. Cereals (38.5 %) and vegetables (23.5 %) were the predominant food categories contributing to ΣEDI, and TEP (29.0 %), TCEP (20.2 %), and TCPP (18.3 %) were three major OPEs contributing to ΣEDI. This study for the first time offered a comprehensive overview of OPE species and revealed their occurrence in foodstuffs from South China.

Investigating the presence of organophosphate esters in sediments from a typical fishing port agglomeration in Dalian, North China

The presence of 14 organophosphate esters (OPEs) in surface sediments from a typical fishing port agglomeration in Dalian, North China was investigated for the first time. Tris(2-ethylhexyl) phosphate (TEHP), triphenylphosphine oxide (TPPO), and tris(2-chloroethyl) phosphate (TCEP) dominated 12 detectable OPEs (∑OPEs), with concentrations ranging widely from 0.56 to 352 ng/g (dry weight basis). The ∑OPE levels in sediments varied significantly across fishing harbors of various grades, and within the same grade, highlighting uneven distribution of OPE sources and inputs to harbors. The first- and second-class fishing harbors had higher geometric mean of ∑OPE contents compared to center and natural harbors, reflecting higher OPE pollution in these areas. Although there were significant correlations among the OPE congeners with high detection frequencies, the composition patterns of sediment OPEs varied considerably among fishing ports. The sediments in the center and first-class harbors had higher abundance of non-chlorinated OPEs (non-Cl-OPEs), suggesting heterogeneity in source strength and pollution characteristics of Cl- and non-Cl-OPEs in fishing ports. The distribution of OPEs in sediments was weakly associated with sediment organic carbon, but not socioeconomic variables, indicating complex controlling factors of their distributions in port sediments. The ecological risks of sediment OPEs were evaluated, and while OPE accumulations ranged broadly (7–684 ng/cm2), exposure hazards were negligible. The sediments in first- and second-class fishing harbors, which had greater OPE accumulation, were identified as reservoirs of OPEs in port aquatic environments.

Distribution and pollution characteristics of organophosphate esters: reflected by tree rings of arbor species.

Organophosphate esters (OPEs) are emerging pollutants. Currently, research on OPEs in tree rings is still limited. In this study, tree rings of five arbor species from Sichuan Province, China, were sampled to study the occurrence and distribution of six OPEs, which were quantitatively analyzed by gas chromatography-mass spectrometry (GC-MS). The total concentrations of OPEs in all samples ranged from 189.79 (Fir species) to 341.23ng/g (Toona sinensis), with average concentration of 284.77 ± 46.66ng/g. So, arbor could be used as good passive samplers for OPEs. The levels of OPEs among five arbor species showed no significant difference (p = 0.668 > 0.05), suggesting that the pollution status of OPEs in a region or country could be roughly assessed by any arbor tree species. In this study area, tris(2-butoxyethyl) phosphate (TBEP) was the dominant OPEs followed by tri(2-chloroethyl) phosphate (TCEP). Tris(2-ethylhexyl) phosphate (TEHP) and tri-n-butyl phosphate (TnBP) showed relatively stable concentrations in each arbor species, while the other four OPEs including TBEP, triphenyl phosphate (TPhP), tri(chloropropyl) phosphate (TCPP) and TCEP had significantly different concentrations. Interestingly, the absorption and accumulation of OPEs by tree rings of arbor species were quite different from that of inorganic elements reported by other studies.

Novel Potentiometric Sensor for Estimation of the Moxifloxacin in the Pharmaceutical Samples, Urine, and Serum

An easy, simple and ecofriendly process for the estimation of moxifloxacin (MFN) in the pharmaceutical samples, serum and blood. The prepared sensors contained moxifloxacin–bromophenol blue as ionphore and, tris(2-ethylhexyl) phosphate, di-butyl phthalate and di-butyl phosphate as plasticizers. The electrodes based on di-n-butyl phthalate (DBPH), Tris (2-ethylhexyl) phosphate (TEHP), and di-butyl phosphate (DBP), gave slope 44.50, 56.86 and 46.38 mV/decade, respectively. The linear concentrations were 1×10-5 - 1×10-2, 5×10-5- 1×10-2 and 5×10-5 - 1×10-2 M with detection limits of 9.0×10-6, 4.7×10-5 and 4.9×10-5 M and a lifetime of 17, 39 and 12 days for electrodes based on DBPH, TEHP, and DBP, respectively. The best electrode was TEHP which gave the best results. The sensor that based on TEHP as plasticizer was better response and stability, it was used to estimate the moxifloxacin in pharmaceutical samples using single and multi-standard addition potentiometry.

New Carbon Paste Sensor for the Determination of Ciprofloxacin in the Pharmaceutical Preparations, Serum and Urine

A quick, novel and highly accurate sensor with superior electrochemical properties have been developed to measure ciprofloxacin in pharmaceutical preparations and human fluids. Three carbon paste sensors for ciprofloxacin (CPF) were produced using the ionophore molecule ciprofloxacin-methyl orange (CPF-MO) in combination with three different plasticizers: di-butyl phthalate (DBPH), di-butyl phosphate (DBP), and tris (2-ethylhexyl)phosphate (TEHP). The slopes of sensors A, B, and C were 59.84, 44.67, and 50.49 mV/decade, respectively. The linear range was 5× 10-5 to 1 ×10-2 M, with detection limits of 4.6×10-5, 4.4×10-5, and 4.9×10-5 M, respectively, and a lifetime of 58, 19, and 21 days. Because sensor A produces the best results, pharmaceutical and human fluids were applied using this sensor; the recovery percentages were 98, 97, 102, 95, and 97 for CPF standard, Bactiflox tablets 500 mg, ciprocin eye drop 0.3%, urine, and serum, respectively, using potential techniques.

Bioaccumulation of organophosphorus flame retardants in marine organisms in Liaodong Bay and their potential ecological risks based on species sensitivity distribution

Although organophosphorus flame retardants (OPFRs) in aquatic environments have received increasing concern, little information is available on their bioaccumulation and trophic transfer in marine food webs. Consequently, the risks of OPFRs to marine ecosystems are unknown. In this study, seven OPFR compounds in marine biological samples collected from Liaodong Bay, Bohai Sea, were analyzed to evaluate their level and biological amplification effect in the marine food web. The total OPFRs of marine organisms in Liaodong Bay ranged from 2.60 to 776 ng/g ww, and lipids were critical factors affecting the concentration of OPFRs in marine species. Tris (2-ethylhexyl) phosphate (TEHP) and tris(1-chloro-2-propyl) phosphate (TCIPP) were the OPFRs most frequently detected in marine species. Still, tris(2-chloroethyl) phosphate (TCEP) was dominant in most marine species (16/24), and the content of chlorinated OPFRs was highest. At the same time, alkyl OPFRs and aryl OPFRs accounted for the same proportion. No correlation between OPFR concentration and the trophic level was observed in marine organisms from Liaodong Bay. It was shown in the results of the species sensitivity distribution that TCIPP in Chinese seawater does not pose a potential ecological risk to marine species. However, much work remains to be done on accumulating information and the ecological risks of OPFRs in different marine food webs.

Mechanisms of flame retardant tris (2-ethylhexyl) phosphate biodegradation via novel bacterial strain Ochrobactrum tritici WX3-8

Tris (2-ethylhexyl) phosphate (TEHP) is a common organophosphorus flame retardant analog with considerable ecological toxicity. Here, novel strain Ochrobactrum tritici WX3-8 capable of degrading TEHP as the sole C source was isolated. Our results show that the strain's TEHP degradation efficiency reached 75% after 104 h under optimal conditions, i.e., 30 °C, pH 7, bacterial inoculum 3%, and<initial concentration 100 mg L−1. The biodegradation efficiency of cell and intracellular enzymes were 75–76%. A consistent degradation trend was observed, with the cellular surface hydrophobicity being increased from 21 to 58% after 24 h while the biodegradation efficiency being increased from 29 to 59% after 20 h. The data indicate that TEHP increased the cell surface for better biosorption to enter the cell more easily, which was decomposed via intracellular enzymes. Furthermore, the membrane permeability increased with time from 1.22 to 1.39 during 104 h degradation, supporting that TEHP changed the surface structure of cells to promote entry into cells for degradation. Further metabolic pathway analysis revealed the possible TEHP biodegradation metabolic pathway as: tri (2-ethylhexyl) phosphate → di (2-ethylhexyl) phosphate → mono (2-ethylhexyl) phosphate → phosphoric acid and generated 2-ethylhexanol. Results showed that TEHP was transformed by O-dealkylation. This research suggests the viability of using novel strain WX3-8 for TEHP as a cost-effective and environmentally-friendly strategy for bioremediation applications of TEHP in the environment.